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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 | * Copyright (C) 2013 Du, Changbin <changbin.du@gmail.com> | |
12 | */ | |
13 | ||
14 | #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__ | |
15 | ||
16 | #include <linux/kernel.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/moduleparam.h> | |
19 | #include <linux/kallsyms.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> | |
27 | #include <linux/string.h> | |
28 | #include <linux/parser.h> | |
29 | #include <linux/string_helpers.h> | |
30 | #include <linux/uaccess.h> | |
31 | #include <linux/dynamic_debug.h> | |
32 | #include <linux/debugfs.h> | |
33 | #include <linux/slab.h> | |
34 | #include <linux/jump_label.h> | |
35 | #include <linux/hardirq.h> | |
36 | #include <linux/sched.h> | |
37 | #include <linux/device.h> | |
38 | #include <linux/netdevice.h> | |
39 | ||
40 | extern struct _ddebug __start___verbose[]; | |
41 | extern struct _ddebug __stop___verbose[]; | |
42 | ||
43 | struct ddebug_table { | |
44 | struct list_head link; | |
45 | const char *mod_name; | |
46 | unsigned int num_ddebugs; | |
47 | struct _ddebug *ddebugs; | |
48 | }; | |
49 | ||
50 | struct ddebug_query { | |
51 | const char *filename; | |
52 | const char *module; | |
53 | const char *function; | |
54 | const char *format; | |
55 | unsigned int first_lineno, last_lineno; | |
56 | }; | |
57 | ||
58 | struct ddebug_iter { | |
59 | struct ddebug_table *table; | |
60 | unsigned int idx; | |
61 | }; | |
62 | ||
63 | static DEFINE_MUTEX(ddebug_lock); | |
64 | static LIST_HEAD(ddebug_tables); | |
65 | static int verbose; | |
66 | module_param(verbose, int, 0644); | |
67 | ||
68 | /* Return the path relative to source root */ | |
69 | static inline const char *trim_prefix(const char *path) | |
70 | { | |
71 | int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c"); | |
72 | ||
73 | if (strncmp(path, __FILE__, skip)) | |
74 | skip = 0; /* prefix mismatch, don't skip */ | |
75 | ||
76 | return path + skip; | |
77 | } | |
78 | ||
79 | static struct { unsigned flag:8; char opt_char; } opt_array[] = { | |
80 | { _DPRINTK_FLAGS_PRINT, 'p' }, | |
81 | { _DPRINTK_FLAGS_INCL_MODNAME, 'm' }, | |
82 | { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' }, | |
83 | { _DPRINTK_FLAGS_INCL_LINENO, 'l' }, | |
84 | { _DPRINTK_FLAGS_INCL_TID, 't' }, | |
85 | { _DPRINTK_FLAGS_NONE, '_' }, | |
86 | }; | |
87 | ||
88 | /* format a string into buf[] which describes the _ddebug's flags */ | |
89 | static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, | |
90 | size_t maxlen) | |
91 | { | |
92 | char *p = buf; | |
93 | int i; | |
94 | ||
95 | BUG_ON(maxlen < 6); | |
96 | for (i = 0; i < ARRAY_SIZE(opt_array); ++i) | |
97 | if (dp->flags & opt_array[i].flag) | |
98 | *p++ = opt_array[i].opt_char; | |
99 | if (p == buf) | |
100 | *p++ = '_'; | |
101 | *p = '\0'; | |
102 | ||
103 | return buf; | |
104 | } | |
105 | ||
106 | #define vpr_info(fmt, ...) \ | |
107 | do { \ | |
108 | if (verbose) \ | |
109 | pr_info(fmt, ##__VA_ARGS__); \ | |
110 | } while (0) | |
111 | ||
112 | static void vpr_info_dq(const struct ddebug_query *query, const char *msg) | |
113 | { | |
114 | /* trim any trailing newlines */ | |
115 | int fmtlen = 0; | |
116 | ||
117 | if (query->format) { | |
118 | fmtlen = strlen(query->format); | |
119 | while (fmtlen && query->format[fmtlen - 1] == '\n') | |
120 | fmtlen--; | |
121 | } | |
122 | ||
123 | vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n", | |
124 | msg, | |
125 | query->function ? query->function : "", | |
126 | query->filename ? query->filename : "", | |
127 | query->module ? query->module : "", | |
128 | fmtlen, query->format ? query->format : "", | |
129 | query->first_lineno, query->last_lineno); | |
130 | } | |
131 | ||
132 | /* | |
133 | * Search the tables for _ddebug's which match the given `query' and | |
134 | * apply the `flags' and `mask' to them. Returns number of matching | |
135 | * callsites, normally the same as number of changes. If verbose, | |
136 | * logs the changes. Takes ddebug_lock. | |
137 | */ | |
138 | static int ddebug_change(const struct ddebug_query *query, | |
139 | unsigned int flags, unsigned int mask) | |
140 | { | |
141 | int i; | |
142 | struct ddebug_table *dt; | |
143 | unsigned int newflags; | |
144 | unsigned int nfound = 0; | |
145 | char flagbuf[10]; | |
146 | ||
147 | /* search for matching ddebugs */ | |
148 | mutex_lock(&ddebug_lock); | |
149 | list_for_each_entry(dt, &ddebug_tables, link) { | |
150 | ||
151 | /* match against the module name */ | |
152 | if (query->module && | |
153 | !match_wildcard(query->module, dt->mod_name)) | |
154 | continue; | |
155 | ||
156 | for (i = 0; i < dt->num_ddebugs; i++) { | |
157 | struct _ddebug *dp = &dt->ddebugs[i]; | |
158 | ||
159 | /* match against the source filename */ | |
160 | if (query->filename && | |
161 | !match_wildcard(query->filename, dp->filename) && | |
162 | !match_wildcard(query->filename, | |
163 | kbasename(dp->filename)) && | |
164 | !match_wildcard(query->filename, | |
165 | trim_prefix(dp->filename))) | |
166 | continue; | |
167 | ||
168 | /* match against the function */ | |
169 | if (query->function && | |
170 | !match_wildcard(query->function, dp->function)) | |
171 | continue; | |
172 | ||
173 | /* match against the format */ | |
174 | if (query->format && | |
175 | !strstr(dp->format, query->format)) | |
176 | continue; | |
177 | ||
178 | /* match against the line number range */ | |
179 | if (query->first_lineno && | |
180 | dp->lineno < query->first_lineno) | |
181 | continue; | |
182 | if (query->last_lineno && | |
183 | dp->lineno > query->last_lineno) | |
184 | continue; | |
185 | ||
186 | nfound++; | |
187 | ||
188 | newflags = (dp->flags & mask) | flags; | |
189 | if (newflags == dp->flags) | |
190 | continue; | |
191 | #ifdef HAVE_JUMP_LABEL | |
192 | if (dp->flags & _DPRINTK_FLAGS_PRINT) { | |
193 | if (!(flags & _DPRINTK_FLAGS_PRINT)) | |
194 | static_branch_disable(&dp->key.dd_key_true); | |
195 | } else if (flags & _DPRINTK_FLAGS_PRINT) | |
196 | static_branch_enable(&dp->key.dd_key_true); | |
197 | #endif | |
198 | dp->flags = newflags; | |
199 | vpr_info("changed %s:%d [%s]%s =%s\n", | |
200 | trim_prefix(dp->filename), dp->lineno, | |
201 | dt->mod_name, dp->function, | |
202 | ddebug_describe_flags(dp, flagbuf, | |
203 | sizeof(flagbuf))); | |
204 | } | |
205 | } | |
206 | mutex_unlock(&ddebug_lock); | |
207 | ||
208 | if (!nfound && verbose) | |
209 | pr_info("no matches for query\n"); | |
210 | ||
211 | return nfound; | |
212 | } | |
213 | ||
214 | /* | |
215 | * Split the buffer `buf' into space-separated words. | |
216 | * Handles simple " and ' quoting, i.e. without nested, | |
217 | * embedded or escaped \". Return the number of words | |
218 | * or <0 on error. | |
219 | */ | |
220 | static int ddebug_tokenize(char *buf, char *words[], int maxwords) | |
221 | { | |
222 | int nwords = 0; | |
223 | ||
224 | while (*buf) { | |
225 | char *end; | |
226 | ||
227 | /* Skip leading whitespace */ | |
228 | buf = skip_spaces(buf); | |
229 | if (!*buf) | |
230 | break; /* oh, it was trailing whitespace */ | |
231 | if (*buf == '#') | |
232 | break; /* token starts comment, skip rest of line */ | |
233 | ||
234 | /* find `end' of word, whitespace separated or quoted */ | |
235 | if (*buf == '"' || *buf == '\'') { | |
236 | int quote = *buf++; | |
237 | for (end = buf; *end && *end != quote; end++) | |
238 | ; | |
239 | if (!*end) { | |
240 | pr_err("unclosed quote: %s\n", buf); | |
241 | return -EINVAL; /* unclosed quote */ | |
242 | } | |
243 | } else { | |
244 | for (end = buf; *end && !isspace(*end); end++) | |
245 | ; | |
246 | BUG_ON(end == buf); | |
247 | } | |
248 | ||
249 | /* `buf' is start of word, `end' is one past its end */ | |
250 | if (nwords == maxwords) { | |
251 | pr_err("too many words, legal max <=%d\n", maxwords); | |
252 | return -EINVAL; /* ran out of words[] before bytes */ | |
253 | } | |
254 | if (*end) | |
255 | *end++ = '\0'; /* terminate the word */ | |
256 | words[nwords++] = buf; | |
257 | buf = end; | |
258 | } | |
259 | ||
260 | if (verbose) { | |
261 | int i; | |
262 | pr_info("split into words:"); | |
263 | for (i = 0; i < nwords; i++) | |
264 | pr_cont(" \"%s\"", words[i]); | |
265 | pr_cont("\n"); | |
266 | } | |
267 | ||
268 | return nwords; | |
269 | } | |
270 | ||
271 | /* | |
272 | * Parse a single line number. Note that the empty string "" | |
273 | * is treated as a special case and converted to zero, which | |
274 | * is later treated as a "don't care" value. | |
275 | */ | |
276 | static inline int parse_lineno(const char *str, unsigned int *val) | |
277 | { | |
278 | BUG_ON(str == NULL); | |
279 | if (*str == '\0') { | |
280 | *val = 0; | |
281 | return 0; | |
282 | } | |
283 | if (kstrtouint(str, 10, val) < 0) { | |
284 | pr_err("bad line-number: %s\n", str); | |
285 | return -EINVAL; | |
286 | } | |
287 | return 0; | |
288 | } | |
289 | ||
290 | static int check_set(const char **dest, char *src, char *name) | |
291 | { | |
292 | int rc = 0; | |
293 | ||
294 | if (*dest) { | |
295 | rc = -EINVAL; | |
296 | pr_err("match-spec:%s val:%s overridden by %s\n", | |
297 | name, *dest, src); | |
298 | } | |
299 | *dest = src; | |
300 | return rc; | |
301 | } | |
302 | ||
303 | /* | |
304 | * Parse words[] as a ddebug query specification, which is a series | |
305 | * of (keyword, value) pairs chosen from these possibilities: | |
306 | * | |
307 | * func <function-name> | |
308 | * file <full-pathname> | |
309 | * file <base-filename> | |
310 | * module <module-name> | |
311 | * format <escaped-string-to-find-in-format> | |
312 | * line <lineno> | |
313 | * line <first-lineno>-<last-lineno> // where either may be empty | |
314 | * | |
315 | * Only 1 of each type is allowed. | |
316 | * Returns 0 on success, <0 on error. | |
317 | */ | |
318 | static int ddebug_parse_query(char *words[], int nwords, | |
319 | struct ddebug_query *query, const char *modname) | |
320 | { | |
321 | unsigned int i; | |
322 | int rc = 0; | |
323 | ||
324 | /* check we have an even number of words */ | |
325 | if (nwords % 2 != 0) { | |
326 | pr_err("expecting pairs of match-spec <value>\n"); | |
327 | return -EINVAL; | |
328 | } | |
329 | memset(query, 0, sizeof(*query)); | |
330 | ||
331 | if (modname) | |
332 | /* support $modname.dyndbg=<multiple queries> */ | |
333 | query->module = modname; | |
334 | ||
335 | for (i = 0; i < nwords; i += 2) { | |
336 | if (!strcmp(words[i], "func")) { | |
337 | rc = check_set(&query->function, words[i+1], "func"); | |
338 | } else if (!strcmp(words[i], "file")) { | |
339 | rc = check_set(&query->filename, words[i+1], "file"); | |
340 | } else if (!strcmp(words[i], "module")) { | |
341 | rc = check_set(&query->module, words[i+1], "module"); | |
342 | } else if (!strcmp(words[i], "format")) { | |
343 | string_unescape_inplace(words[i+1], UNESCAPE_SPACE | | |
344 | UNESCAPE_OCTAL | | |
345 | UNESCAPE_SPECIAL); | |
346 | rc = check_set(&query->format, words[i+1], "format"); | |
347 | } else if (!strcmp(words[i], "line")) { | |
348 | char *first = words[i+1]; | |
349 | char *last = strchr(first, '-'); | |
350 | if (query->first_lineno || query->last_lineno) { | |
351 | pr_err("match-spec: line used 2x\n"); | |
352 | return -EINVAL; | |
353 | } | |
354 | if (last) | |
355 | *last++ = '\0'; | |
356 | if (parse_lineno(first, &query->first_lineno) < 0) | |
357 | return -EINVAL; | |
358 | if (last) { | |
359 | /* range <first>-<last> */ | |
360 | if (parse_lineno(last, &query->last_lineno) < 0) | |
361 | return -EINVAL; | |
362 | ||
363 | if (query->last_lineno < query->first_lineno) { | |
364 | pr_err("last-line:%d < 1st-line:%d\n", | |
365 | query->last_lineno, | |
366 | query->first_lineno); | |
367 | return -EINVAL; | |
368 | } | |
369 | } else { | |
370 | query->last_lineno = query->first_lineno; | |
371 | } | |
372 | } else { | |
373 | pr_err("unknown keyword \"%s\"\n", words[i]); | |
374 | return -EINVAL; | |
375 | } | |
376 | if (rc) | |
377 | return rc; | |
378 | } | |
379 | vpr_info_dq(query, "parsed"); | |
380 | return 0; | |
381 | } | |
382 | ||
383 | /* | |
384 | * Parse `str' as a flags specification, format [-+=][p]+. | |
385 | * Sets up *maskp and *flagsp to be used when changing the | |
386 | * flags fields of matched _ddebug's. Returns 0 on success | |
387 | * or <0 on error. | |
388 | */ | |
389 | static int ddebug_parse_flags(const char *str, unsigned int *flagsp, | |
390 | unsigned int *maskp) | |
391 | { | |
392 | unsigned flags = 0; | |
393 | int op = '=', i; | |
394 | ||
395 | switch (*str) { | |
396 | case '+': | |
397 | case '-': | |
398 | case '=': | |
399 | op = *str++; | |
400 | break; | |
401 | default: | |
402 | pr_err("bad flag-op %c, at start of %s\n", *str, str); | |
403 | return -EINVAL; | |
404 | } | |
405 | vpr_info("op='%c'\n", op); | |
406 | ||
407 | for (; *str ; ++str) { | |
408 | for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) { | |
409 | if (*str == opt_array[i].opt_char) { | |
410 | flags |= opt_array[i].flag; | |
411 | break; | |
412 | } | |
413 | } | |
414 | if (i < 0) { | |
415 | pr_err("unknown flag '%c' in \"%s\"\n", *str, str); | |
416 | return -EINVAL; | |
417 | } | |
418 | } | |
419 | vpr_info("flags=0x%x\n", flags); | |
420 | ||
421 | /* calculate final *flagsp, *maskp according to mask and op */ | |
422 | switch (op) { | |
423 | case '=': | |
424 | *maskp = 0; | |
425 | *flagsp = flags; | |
426 | break; | |
427 | case '+': | |
428 | *maskp = ~0U; | |
429 | *flagsp = flags; | |
430 | break; | |
431 | case '-': | |
432 | *maskp = ~flags; | |
433 | *flagsp = 0; | |
434 | break; | |
435 | } | |
436 | vpr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp); | |
437 | return 0; | |
438 | } | |
439 | ||
440 | static int ddebug_exec_query(char *query_string, const char *modname) | |
441 | { | |
442 | unsigned int flags = 0, mask = 0; | |
443 | struct ddebug_query query; | |
444 | #define MAXWORDS 9 | |
445 | int nwords, nfound; | |
446 | char *words[MAXWORDS]; | |
447 | ||
448 | nwords = ddebug_tokenize(query_string, words, MAXWORDS); | |
449 | if (nwords <= 0) { | |
450 | pr_err("tokenize failed\n"); | |
451 | return -EINVAL; | |
452 | } | |
453 | /* check flags 1st (last arg) so query is pairs of spec,val */ | |
454 | if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) { | |
455 | pr_err("flags parse failed\n"); | |
456 | return -EINVAL; | |
457 | } | |
458 | if (ddebug_parse_query(words, nwords-1, &query, modname)) { | |
459 | pr_err("query parse failed\n"); | |
460 | return -EINVAL; | |
461 | } | |
462 | /* actually go and implement the change */ | |
463 | nfound = ddebug_change(&query, flags, mask); | |
464 | vpr_info_dq(&query, nfound ? "applied" : "no-match"); | |
465 | ||
466 | return nfound; | |
467 | } | |
468 | ||
469 | /* handle multiple queries in query string, continue on error, return | |
470 | last error or number of matching callsites. Module name is either | |
471 | in param (for boot arg) or perhaps in query string. | |
472 | */ | |
473 | static int ddebug_exec_queries(char *query, const char *modname) | |
474 | { | |
475 | char *split; | |
476 | int i, errs = 0, exitcode = 0, rc, nfound = 0; | |
477 | ||
478 | for (i = 0; query; query = split) { | |
479 | split = strpbrk(query, ";\n"); | |
480 | if (split) | |
481 | *split++ = '\0'; | |
482 | ||
483 | query = skip_spaces(query); | |
484 | if (!query || !*query || *query == '#') | |
485 | continue; | |
486 | ||
487 | vpr_info("query %d: \"%s\"\n", i, query); | |
488 | ||
489 | rc = ddebug_exec_query(query, modname); | |
490 | if (rc < 0) { | |
491 | errs++; | |
492 | exitcode = rc; | |
493 | } else { | |
494 | nfound += rc; | |
495 | } | |
496 | i++; | |
497 | } | |
498 | vpr_info("processed %d queries, with %d matches, %d errs\n", | |
499 | i, nfound, errs); | |
500 | ||
501 | if (exitcode) | |
502 | return exitcode; | |
503 | return nfound; | |
504 | } | |
505 | ||
506 | #define PREFIX_SIZE 64 | |
507 | ||
508 | static int remaining(int wrote) | |
509 | { | |
510 | if (PREFIX_SIZE - wrote > 0) | |
511 | return PREFIX_SIZE - wrote; | |
512 | return 0; | |
513 | } | |
514 | ||
515 | static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf) | |
516 | { | |
517 | int pos_after_tid; | |
518 | int pos = 0; | |
519 | ||
520 | *buf = '\0'; | |
521 | ||
522 | if (desc->flags & _DPRINTK_FLAGS_INCL_TID) { | |
523 | if (in_interrupt()) | |
524 | pos += snprintf(buf + pos, remaining(pos), "<intr> "); | |
525 | else | |
526 | pos += snprintf(buf + pos, remaining(pos), "[%d] ", | |
527 | task_pid_vnr(current)); | |
528 | } | |
529 | pos_after_tid = pos; | |
530 | if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME) | |
531 | pos += snprintf(buf + pos, remaining(pos), "%s:", | |
532 | desc->modname); | |
533 | if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME) | |
534 | pos += snprintf(buf + pos, remaining(pos), "%s:", | |
535 | desc->function); | |
536 | if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO) | |
537 | pos += snprintf(buf + pos, remaining(pos), "%d:", | |
538 | desc->lineno); | |
539 | if (pos - pos_after_tid) | |
540 | pos += snprintf(buf + pos, remaining(pos), " "); | |
541 | if (pos >= PREFIX_SIZE) | |
542 | buf[PREFIX_SIZE - 1] = '\0'; | |
543 | ||
544 | return buf; | |
545 | } | |
546 | ||
547 | void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...) | |
548 | { | |
549 | va_list args; | |
550 | struct va_format vaf; | |
551 | char buf[PREFIX_SIZE]; | |
552 | ||
553 | BUG_ON(!descriptor); | |
554 | BUG_ON(!fmt); | |
555 | ||
556 | va_start(args, fmt); | |
557 | ||
558 | vaf.fmt = fmt; | |
559 | vaf.va = &args; | |
560 | ||
561 | printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf); | |
562 | ||
563 | va_end(args); | |
564 | } | |
565 | EXPORT_SYMBOL(__dynamic_pr_debug); | |
566 | ||
567 | void __dynamic_dev_dbg(struct _ddebug *descriptor, | |
568 | const struct device *dev, const char *fmt, ...) | |
569 | { | |
570 | struct va_format vaf; | |
571 | va_list args; | |
572 | ||
573 | BUG_ON(!descriptor); | |
574 | BUG_ON(!fmt); | |
575 | ||
576 | va_start(args, fmt); | |
577 | ||
578 | vaf.fmt = fmt; | |
579 | vaf.va = &args; | |
580 | ||
581 | if (!dev) { | |
582 | printk(KERN_DEBUG "(NULL device *): %pV", &vaf); | |
583 | } else { | |
584 | char buf[PREFIX_SIZE]; | |
585 | ||
586 | dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV", | |
587 | dynamic_emit_prefix(descriptor, buf), | |
588 | dev_driver_string(dev), dev_name(dev), | |
589 | &vaf); | |
590 | } | |
591 | ||
592 | va_end(args); | |
593 | } | |
594 | EXPORT_SYMBOL(__dynamic_dev_dbg); | |
595 | ||
596 | #ifdef CONFIG_NET | |
597 | ||
598 | void __dynamic_netdev_dbg(struct _ddebug *descriptor, | |
599 | const struct net_device *dev, const char *fmt, ...) | |
600 | { | |
601 | struct va_format vaf; | |
602 | va_list args; | |
603 | ||
604 | BUG_ON(!descriptor); | |
605 | BUG_ON(!fmt); | |
606 | ||
607 | va_start(args, fmt); | |
608 | ||
609 | vaf.fmt = fmt; | |
610 | vaf.va = &args; | |
611 | ||
612 | if (dev && dev->dev.parent) { | |
613 | char buf[PREFIX_SIZE]; | |
614 | ||
615 | dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent, | |
616 | "%s%s %s %s%s: %pV", | |
617 | dynamic_emit_prefix(descriptor, buf), | |
618 | dev_driver_string(dev->dev.parent), | |
619 | dev_name(dev->dev.parent), | |
620 | netdev_name(dev), netdev_reg_state(dev), | |
621 | &vaf); | |
622 | } else if (dev) { | |
623 | printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev), | |
624 | netdev_reg_state(dev), &vaf); | |
625 | } else { | |
626 | printk(KERN_DEBUG "(NULL net_device): %pV", &vaf); | |
627 | } | |
628 | ||
629 | va_end(args); | |
630 | } | |
631 | EXPORT_SYMBOL(__dynamic_netdev_dbg); | |
632 | ||
633 | #endif | |
634 | ||
635 | #define DDEBUG_STRING_SIZE 1024 | |
636 | static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE]; | |
637 | ||
638 | static __init int ddebug_setup_query(char *str) | |
639 | { | |
640 | if (strlen(str) >= DDEBUG_STRING_SIZE) { | |
641 | pr_warn("ddebug boot param string too large\n"); | |
642 | return 0; | |
643 | } | |
644 | strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE); | |
645 | return 1; | |
646 | } | |
647 | ||
648 | __setup("ddebug_query=", ddebug_setup_query); | |
649 | ||
650 | /* | |
651 | * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the | |
652 | * command text from userspace, parses and executes it. | |
653 | */ | |
654 | #define USER_BUF_PAGE 4096 | |
655 | static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, | |
656 | size_t len, loff_t *offp) | |
657 | { | |
658 | char *tmpbuf; | |
659 | int ret; | |
660 | ||
661 | if (len == 0) | |
662 | return 0; | |
663 | if (len > USER_BUF_PAGE - 1) { | |
664 | pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE); | |
665 | return -E2BIG; | |
666 | } | |
667 | tmpbuf = memdup_user_nul(ubuf, len); | |
668 | if (IS_ERR(tmpbuf)) | |
669 | return PTR_ERR(tmpbuf); | |
670 | vpr_info("read %d bytes from userspace\n", (int)len); | |
671 | ||
672 | ret = ddebug_exec_queries(tmpbuf, NULL); | |
673 | kfree(tmpbuf); | |
674 | if (ret < 0) | |
675 | return ret; | |
676 | ||
677 | *offp += len; | |
678 | return len; | |
679 | } | |
680 | ||
681 | /* | |
682 | * Set the iterator to point to the first _ddebug object | |
683 | * and return a pointer to that first object. Returns | |
684 | * NULL if there are no _ddebugs at all. | |
685 | */ | |
686 | static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter) | |
687 | { | |
688 | if (list_empty(&ddebug_tables)) { | |
689 | iter->table = NULL; | |
690 | iter->idx = 0; | |
691 | return NULL; | |
692 | } | |
693 | iter->table = list_entry(ddebug_tables.next, | |
694 | struct ddebug_table, link); | |
695 | iter->idx = 0; | |
696 | return &iter->table->ddebugs[iter->idx]; | |
697 | } | |
698 | ||
699 | /* | |
700 | * Advance the iterator to point to the next _ddebug | |
701 | * object from the one the iterator currently points at, | |
702 | * and returns a pointer to the new _ddebug. Returns | |
703 | * NULL if the iterator has seen all the _ddebugs. | |
704 | */ | |
705 | static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter) | |
706 | { | |
707 | if (iter->table == NULL) | |
708 | return NULL; | |
709 | if (++iter->idx == iter->table->num_ddebugs) { | |
710 | /* iterate to next table */ | |
711 | iter->idx = 0; | |
712 | if (list_is_last(&iter->table->link, &ddebug_tables)) { | |
713 | iter->table = NULL; | |
714 | return NULL; | |
715 | } | |
716 | iter->table = list_entry(iter->table->link.next, | |
717 | struct ddebug_table, link); | |
718 | } | |
719 | return &iter->table->ddebugs[iter->idx]; | |
720 | } | |
721 | ||
722 | /* | |
723 | * Seq_ops start method. Called at the start of every | |
724 | * read() call from userspace. Takes the ddebug_lock and | |
725 | * seeks the seq_file's iterator to the given position. | |
726 | */ | |
727 | static void *ddebug_proc_start(struct seq_file *m, loff_t *pos) | |
728 | { | |
729 | struct ddebug_iter *iter = m->private; | |
730 | struct _ddebug *dp; | |
731 | int n = *pos; | |
732 | ||
733 | vpr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos); | |
734 | ||
735 | mutex_lock(&ddebug_lock); | |
736 | ||
737 | if (!n) | |
738 | return SEQ_START_TOKEN; | |
739 | if (n < 0) | |
740 | return NULL; | |
741 | dp = ddebug_iter_first(iter); | |
742 | while (dp != NULL && --n > 0) | |
743 | dp = ddebug_iter_next(iter); | |
744 | return dp; | |
745 | } | |
746 | ||
747 | /* | |
748 | * Seq_ops next method. Called several times within a read() | |
749 | * call from userspace, with ddebug_lock held. Walks to the | |
750 | * next _ddebug object with a special case for the header line. | |
751 | */ | |
752 | static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos) | |
753 | { | |
754 | struct ddebug_iter *iter = m->private; | |
755 | struct _ddebug *dp; | |
756 | ||
757 | vpr_info("called m=%p p=%p *pos=%lld\n", | |
758 | m, p, (unsigned long long)*pos); | |
759 | ||
760 | if (p == SEQ_START_TOKEN) | |
761 | dp = ddebug_iter_first(iter); | |
762 | else | |
763 | dp = ddebug_iter_next(iter); | |
764 | ++*pos; | |
765 | return dp; | |
766 | } | |
767 | ||
768 | /* | |
769 | * Seq_ops show method. Called several times within a read() | |
770 | * call from userspace, with ddebug_lock held. Formats the | |
771 | * current _ddebug as a single human-readable line, with a | |
772 | * special case for the header line. | |
773 | */ | |
774 | static int ddebug_proc_show(struct seq_file *m, void *p) | |
775 | { | |
776 | struct ddebug_iter *iter = m->private; | |
777 | struct _ddebug *dp = p; | |
778 | char flagsbuf[10]; | |
779 | ||
780 | vpr_info("called m=%p p=%p\n", m, p); | |
781 | ||
782 | if (p == SEQ_START_TOKEN) { | |
783 | seq_puts(m, | |
784 | "# filename:lineno [module]function flags format\n"); | |
785 | return 0; | |
786 | } | |
787 | ||
788 | seq_printf(m, "%s:%u [%s]%s =%s \"", | |
789 | trim_prefix(dp->filename), dp->lineno, | |
790 | iter->table->mod_name, dp->function, | |
791 | ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf))); | |
792 | seq_escape(m, dp->format, "\t\r\n\""); | |
793 | seq_puts(m, "\"\n"); | |
794 | ||
795 | return 0; | |
796 | } | |
797 | ||
798 | /* | |
799 | * Seq_ops stop method. Called at the end of each read() | |
800 | * call from userspace. Drops ddebug_lock. | |
801 | */ | |
802 | static void ddebug_proc_stop(struct seq_file *m, void *p) | |
803 | { | |
804 | vpr_info("called m=%p p=%p\n", m, p); | |
805 | mutex_unlock(&ddebug_lock); | |
806 | } | |
807 | ||
808 | static const struct seq_operations ddebug_proc_seqops = { | |
809 | .start = ddebug_proc_start, | |
810 | .next = ddebug_proc_next, | |
811 | .show = ddebug_proc_show, | |
812 | .stop = ddebug_proc_stop | |
813 | }; | |
814 | ||
815 | /* | |
816 | * File_ops->open method for <debugfs>/dynamic_debug/control. Does | |
817 | * the seq_file setup dance, and also creates an iterator to walk the | |
818 | * _ddebugs. Note that we create a seq_file always, even for O_WRONLY | |
819 | * files where it's not needed, as doing so simplifies the ->release | |
820 | * method. | |
821 | */ | |
822 | static int ddebug_proc_open(struct inode *inode, struct file *file) | |
823 | { | |
824 | vpr_info("called\n"); | |
825 | return seq_open_private(file, &ddebug_proc_seqops, | |
826 | sizeof(struct ddebug_iter)); | |
827 | } | |
828 | ||
829 | static const struct file_operations ddebug_proc_fops = { | |
830 | .owner = THIS_MODULE, | |
831 | .open = ddebug_proc_open, | |
832 | .read = seq_read, | |
833 | .llseek = seq_lseek, | |
834 | .release = seq_release_private, | |
835 | .write = ddebug_proc_write | |
836 | }; | |
837 | ||
838 | /* | |
839 | * Allocate a new ddebug_table for the given module | |
840 | * and add it to the global list. | |
841 | */ | |
842 | int ddebug_add_module(struct _ddebug *tab, unsigned int n, | |
843 | const char *name) | |
844 | { | |
845 | struct ddebug_table *dt; | |
846 | const char *new_name; | |
847 | ||
848 | dt = kzalloc(sizeof(*dt), GFP_KERNEL); | |
849 | if (dt == NULL) | |
850 | return -ENOMEM; | |
851 | new_name = kstrdup_const(name, GFP_KERNEL); | |
852 | if (new_name == NULL) { | |
853 | kfree(dt); | |
854 | return -ENOMEM; | |
855 | } | |
856 | dt->mod_name = new_name; | |
857 | dt->num_ddebugs = n; | |
858 | dt->ddebugs = tab; | |
859 | ||
860 | mutex_lock(&ddebug_lock); | |
861 | list_add_tail(&dt->link, &ddebug_tables); | |
862 | mutex_unlock(&ddebug_lock); | |
863 | ||
864 | vpr_info("%u debug prints in module %s\n", n, dt->mod_name); | |
865 | return 0; | |
866 | } | |
867 | EXPORT_SYMBOL_GPL(ddebug_add_module); | |
868 | ||
869 | /* helper for ddebug_dyndbg_(boot|module)_param_cb */ | |
870 | static int ddebug_dyndbg_param_cb(char *param, char *val, | |
871 | const char *modname, int on_err) | |
872 | { | |
873 | char *sep; | |
874 | ||
875 | sep = strchr(param, '.'); | |
876 | if (sep) { | |
877 | /* needed only for ddebug_dyndbg_boot_param_cb */ | |
878 | *sep = '\0'; | |
879 | modname = param; | |
880 | param = sep + 1; | |
881 | } | |
882 | if (strcmp(param, "dyndbg")) | |
883 | return on_err; /* determined by caller */ | |
884 | ||
885 | ddebug_exec_queries((val ? val : "+p"), modname); | |
886 | ||
887 | return 0; /* query failure shouldnt stop module load */ | |
888 | } | |
889 | ||
890 | /* handle both dyndbg and $module.dyndbg params at boot */ | |
891 | static int ddebug_dyndbg_boot_param_cb(char *param, char *val, | |
892 | const char *unused, void *arg) | |
893 | { | |
894 | vpr_info("%s=\"%s\"\n", param, val); | |
895 | return ddebug_dyndbg_param_cb(param, val, NULL, 0); | |
896 | } | |
897 | ||
898 | /* | |
899 | * modprobe foo finds foo.params in boot-args, strips "foo.", and | |
900 | * passes them to load_module(). This callback gets unknown params, | |
901 | * processes dyndbg params, rejects others. | |
902 | */ | |
903 | int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module) | |
904 | { | |
905 | vpr_info("module: %s %s=\"%s\"\n", module, param, val); | |
906 | return ddebug_dyndbg_param_cb(param, val, module, -ENOENT); | |
907 | } | |
908 | ||
909 | static void ddebug_table_free(struct ddebug_table *dt) | |
910 | { | |
911 | list_del_init(&dt->link); | |
912 | kfree_const(dt->mod_name); | |
913 | kfree(dt); | |
914 | } | |
915 | ||
916 | /* | |
917 | * Called in response to a module being unloaded. Removes | |
918 | * any ddebug_table's which point at the module. | |
919 | */ | |
920 | int ddebug_remove_module(const char *mod_name) | |
921 | { | |
922 | struct ddebug_table *dt, *nextdt; | |
923 | int ret = -ENOENT; | |
924 | ||
925 | vpr_info("removing module \"%s\"\n", mod_name); | |
926 | ||
927 | mutex_lock(&ddebug_lock); | |
928 | list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) { | |
929 | if (!strcmp(dt->mod_name, mod_name)) { | |
930 | ddebug_table_free(dt); | |
931 | ret = 0; | |
932 | } | |
933 | } | |
934 | mutex_unlock(&ddebug_lock); | |
935 | return ret; | |
936 | } | |
937 | EXPORT_SYMBOL_GPL(ddebug_remove_module); | |
938 | ||
939 | static void ddebug_remove_all_tables(void) | |
940 | { | |
941 | mutex_lock(&ddebug_lock); | |
942 | while (!list_empty(&ddebug_tables)) { | |
943 | struct ddebug_table *dt = list_entry(ddebug_tables.next, | |
944 | struct ddebug_table, | |
945 | link); | |
946 | ddebug_table_free(dt); | |
947 | } | |
948 | mutex_unlock(&ddebug_lock); | |
949 | } | |
950 | ||
951 | static __initdata int ddebug_init_success; | |
952 | ||
953 | static int __init dynamic_debug_init_debugfs(void) | |
954 | { | |
955 | struct dentry *dir, *file; | |
956 | ||
957 | if (!ddebug_init_success) | |
958 | return -ENODEV; | |
959 | ||
960 | dir = debugfs_create_dir("dynamic_debug", NULL); | |
961 | if (!dir) | |
962 | return -ENOMEM; | |
963 | file = debugfs_create_file("control", 0644, dir, NULL, | |
964 | &ddebug_proc_fops); | |
965 | if (!file) { | |
966 | debugfs_remove(dir); | |
967 | return -ENOMEM; | |
968 | } | |
969 | return 0; | |
970 | } | |
971 | ||
972 | static int __init dynamic_debug_init(void) | |
973 | { | |
974 | struct _ddebug *iter, *iter_start; | |
975 | const char *modname = NULL; | |
976 | char *cmdline; | |
977 | int ret = 0; | |
978 | int n = 0, entries = 0, modct = 0; | |
979 | int verbose_bytes = 0; | |
980 | ||
981 | if (__start___verbose == __stop___verbose) { | |
982 | pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n"); | |
983 | return 1; | |
984 | } | |
985 | iter = __start___verbose; | |
986 | modname = iter->modname; | |
987 | iter_start = iter; | |
988 | for (; iter < __stop___verbose; iter++) { | |
989 | entries++; | |
990 | verbose_bytes += strlen(iter->modname) + strlen(iter->function) | |
991 | + strlen(iter->filename) + strlen(iter->format); | |
992 | ||
993 | if (strcmp(modname, iter->modname)) { | |
994 | modct++; | |
995 | ret = ddebug_add_module(iter_start, n, modname); | |
996 | if (ret) | |
997 | goto out_err; | |
998 | n = 0; | |
999 | modname = iter->modname; | |
1000 | iter_start = iter; | |
1001 | } | |
1002 | n++; | |
1003 | } | |
1004 | ret = ddebug_add_module(iter_start, n, modname); | |
1005 | if (ret) | |
1006 | goto out_err; | |
1007 | ||
1008 | ddebug_init_success = 1; | |
1009 | vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in (readonly) verbose section\n", | |
1010 | modct, entries, (int)(modct * sizeof(struct ddebug_table)), | |
1011 | verbose_bytes + (int)(__stop___verbose - __start___verbose)); | |
1012 | ||
1013 | /* apply ddebug_query boot param, dont unload tables on err */ | |
1014 | if (ddebug_setup_string[0] != '\0') { | |
1015 | pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n"); | |
1016 | ret = ddebug_exec_queries(ddebug_setup_string, NULL); | |
1017 | if (ret < 0) | |
1018 | pr_warn("Invalid ddebug boot param %s\n", | |
1019 | ddebug_setup_string); | |
1020 | else | |
1021 | pr_info("%d changes by ddebug_query\n", ret); | |
1022 | } | |
1023 | /* now that ddebug tables are loaded, process all boot args | |
1024 | * again to find and activate queries given in dyndbg params. | |
1025 | * While this has already been done for known boot params, it | |
1026 | * ignored the unknown ones (dyndbg in particular). Reusing | |
1027 | * parse_args avoids ad-hoc parsing. This will also attempt | |
1028 | * to activate queries for not-yet-loaded modules, which is | |
1029 | * slightly noisy if verbose, but harmless. | |
1030 | */ | |
1031 | cmdline = kstrdup(saved_command_line, GFP_KERNEL); | |
1032 | parse_args("dyndbg params", cmdline, NULL, | |
1033 | 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb); | |
1034 | kfree(cmdline); | |
1035 | return 0; | |
1036 | ||
1037 | out_err: | |
1038 | ddebug_remove_all_tables(); | |
1039 | return 0; | |
1040 | } | |
1041 | /* Allow early initialization for boot messages via boot param */ | |
1042 | early_initcall(dynamic_debug_init); | |
1043 | ||
1044 | /* Debugfs setup must be done later */ | |
1045 | fs_initcall(dynamic_debug_init_debugfs); |