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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 | #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__ | |
14 | ||
15 | #include <linux/kernel.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/moduleparam.h> | |
18 | #include <linux/kallsyms.h> | |
19 | #include <linux/types.h> | |
20 | #include <linux/mutex.h> | |
21 | #include <linux/proc_fs.h> | |
22 | #include <linux/seq_file.h> | |
23 | #include <linux/list.h> | |
24 | #include <linux/sysctl.h> | |
25 | #include <linux/ctype.h> | |
26 | #include <linux/string.h> | |
27 | #include <linux/string_helpers.h> | |
28 | #include <linux/uaccess.h> | |
29 | #include <linux/dynamic_debug.h> | |
30 | #include <linux/debugfs.h> | |
31 | #include <linux/slab.h> | |
32 | #include <linux/jump_label.h> | |
33 | #include <linux/hardirq.h> | |
34 | #include <linux/sched.h> | |
35 | #include <linux/device.h> | |
36 | #include <linux/netdevice.h> | |
37 | ||
38 | extern struct _ddebug __start___verbose[]; | |
39 | extern struct _ddebug __stop___verbose[]; | |
40 | ||
41 | struct ddebug_table { | |
42 | struct list_head link; | |
43 | char *mod_name; | |
44 | unsigned int num_ddebugs; | |
45 | struct _ddebug *ddebugs; | |
46 | }; | |
47 | ||
48 | struct 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 | ||
56 | struct ddebug_iter { | |
57 | struct ddebug_table *table; | |
58 | unsigned int idx; | |
59 | }; | |
60 | ||
61 | static DEFINE_MUTEX(ddebug_lock); | |
62 | static LIST_HEAD(ddebug_tables); | |
63 | static int verbose; | |
64 | module_param(verbose, int, 0644); | |
65 | ||
66 | /* Return the path relative to source root */ | |
67 | static inline const char *trim_prefix(const char *path) | |
68 | { | |
69 | int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c"); | |
70 | ||
71 | if (strncmp(path, __FILE__, skip)) | |
72 | skip = 0; /* prefix mismatch, don't skip */ | |
73 | ||
74 | return path + skip; | |
75 | } | |
76 | ||
77 | static struct { unsigned flag:8; char opt_char; } opt_array[] = { | |
78 | { _DPRINTK_FLAGS_PRINT, 'p' }, | |
79 | { _DPRINTK_FLAGS_INCL_MODNAME, 'm' }, | |
80 | { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' }, | |
81 | { _DPRINTK_FLAGS_INCL_LINENO, 'l' }, | |
82 | { _DPRINTK_FLAGS_INCL_TID, 't' }, | |
83 | { _DPRINTK_FLAGS_NONE, '_' }, | |
84 | }; | |
85 | ||
86 | /* format a string into buf[] which describes the _ddebug's flags */ | |
87 | static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, | |
88 | size_t maxlen) | |
89 | { | |
90 | char *p = buf; | |
91 | int i; | |
92 | ||
93 | BUG_ON(maxlen < 6); | |
94 | for (i = 0; i < ARRAY_SIZE(opt_array); ++i) | |
95 | if (dp->flags & opt_array[i].flag) | |
96 | *p++ = opt_array[i].opt_char; | |
97 | if (p == buf) | |
98 | *p++ = '_'; | |
99 | *p = '\0'; | |
100 | ||
101 | return buf; | |
102 | } | |
103 | ||
104 | #define vpr_info(fmt, ...) \ | |
105 | do { \ | |
106 | if (verbose) \ | |
107 | pr_info(fmt, ##__VA_ARGS__); \ | |
108 | } while (0) | |
109 | ||
110 | static void vpr_info_dq(const struct ddebug_query *query, const char *msg) | |
111 | { | |
112 | /* trim any trailing newlines */ | |
113 | int fmtlen = 0; | |
114 | ||
115 | if (query->format) { | |
116 | fmtlen = strlen(query->format); | |
117 | while (fmtlen && query->format[fmtlen - 1] == '\n') | |
118 | fmtlen--; | |
119 | } | |
120 | ||
121 | vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n", | |
122 | msg, | |
123 | query->function ? query->function : "", | |
124 | query->filename ? query->filename : "", | |
125 | query->module ? query->module : "", | |
126 | fmtlen, query->format ? query->format : "", | |
127 | query->first_lineno, query->last_lineno); | |
128 | } | |
129 | ||
130 | /* | |
131 | * Search the tables for _ddebug's which match the given `query' and | |
132 | * apply the `flags' and `mask' to them. Returns number of matching | |
133 | * callsites, normally the same as number of changes. If verbose, | |
134 | * logs the changes. Takes ddebug_lock. | |
135 | */ | |
136 | static int ddebug_change(const struct ddebug_query *query, | |
137 | unsigned int flags, unsigned int mask) | |
138 | { | |
139 | int i; | |
140 | struct ddebug_table *dt; | |
141 | unsigned int newflags; | |
142 | unsigned int nfound = 0; | |
143 | char flagbuf[10]; | |
144 | ||
145 | /* search for matching ddebugs */ | |
146 | mutex_lock(&ddebug_lock); | |
147 | list_for_each_entry(dt, &ddebug_tables, link) { | |
148 | ||
149 | /* match against the module name */ | |
150 | if (query->module && strcmp(query->module, dt->mod_name)) | |
151 | continue; | |
152 | ||
153 | for (i = 0; i < dt->num_ddebugs; i++) { | |
154 | struct _ddebug *dp = &dt->ddebugs[i]; | |
155 | ||
156 | /* match against the source filename */ | |
157 | if (query->filename && | |
158 | strcmp(query->filename, dp->filename) && | |
159 | strcmp(query->filename, kbasename(dp->filename)) && | |
160 | strcmp(query->filename, trim_prefix(dp->filename))) | |
161 | continue; | |
162 | ||
163 | /* match against the function */ | |
164 | if (query->function && | |
165 | strcmp(query->function, dp->function)) | |
166 | continue; | |
167 | ||
168 | /* match against the format */ | |
169 | if (query->format && | |
170 | !strstr(dp->format, query->format)) | |
171 | continue; | |
172 | ||
173 | /* match against the line number range */ | |
174 | if (query->first_lineno && | |
175 | dp->lineno < query->first_lineno) | |
176 | continue; | |
177 | if (query->last_lineno && | |
178 | dp->lineno > query->last_lineno) | |
179 | continue; | |
180 | ||
181 | nfound++; | |
182 | ||
183 | newflags = (dp->flags & mask) | flags; | |
184 | if (newflags == dp->flags) | |
185 | continue; | |
186 | dp->flags = newflags; | |
187 | vpr_info("changed %s:%d [%s]%s =%s\n", | |
188 | trim_prefix(dp->filename), dp->lineno, | |
189 | dt->mod_name, dp->function, | |
190 | ddebug_describe_flags(dp, flagbuf, | |
191 | sizeof(flagbuf))); | |
192 | } | |
193 | } | |
194 | mutex_unlock(&ddebug_lock); | |
195 | ||
196 | if (!nfound && verbose) | |
197 | pr_info("no matches for query\n"); | |
198 | ||
199 | return nfound; | |
200 | } | |
201 | ||
202 | /* | |
203 | * Split the buffer `buf' into space-separated words. | |
204 | * Handles simple " and ' quoting, i.e. without nested, | |
205 | * embedded or escaped \". Return the number of words | |
206 | * or <0 on error. | |
207 | */ | |
208 | static int ddebug_tokenize(char *buf, char *words[], int maxwords) | |
209 | { | |
210 | int nwords = 0; | |
211 | ||
212 | while (*buf) { | |
213 | char *end; | |
214 | ||
215 | /* Skip leading whitespace */ | |
216 | buf = skip_spaces(buf); | |
217 | if (!*buf) | |
218 | break; /* oh, it was trailing whitespace */ | |
219 | if (*buf == '#') | |
220 | break; /* token starts comment, skip rest of line */ | |
221 | ||
222 | /* find `end' of word, whitespace separated or quoted */ | |
223 | if (*buf == '"' || *buf == '\'') { | |
224 | int quote = *buf++; | |
225 | for (end = buf; *end && *end != quote; end++) | |
226 | ; | |
227 | if (!*end) { | |
228 | pr_err("unclosed quote: %s\n", buf); | |
229 | return -EINVAL; /* unclosed quote */ | |
230 | } | |
231 | } else { | |
232 | for (end = buf; *end && !isspace(*end); end++) | |
233 | ; | |
234 | BUG_ON(end == buf); | |
235 | } | |
236 | ||
237 | /* `buf' is start of word, `end' is one past its end */ | |
238 | if (nwords == maxwords) { | |
239 | pr_err("too many words, legal max <=%d\n", maxwords); | |
240 | return -EINVAL; /* ran out of words[] before bytes */ | |
241 | } | |
242 | if (*end) | |
243 | *end++ = '\0'; /* terminate the word */ | |
244 | words[nwords++] = buf; | |
245 | buf = end; | |
246 | } | |
247 | ||
248 | if (verbose) { | |
249 | int i; | |
250 | pr_info("split into words:"); | |
251 | for (i = 0; i < nwords; i++) | |
252 | pr_cont(" \"%s\"", words[i]); | |
253 | pr_cont("\n"); | |
254 | } | |
255 | ||
256 | return nwords; | |
257 | } | |
258 | ||
259 | /* | |
260 | * Parse a single line number. Note that the empty string "" | |
261 | * is treated as a special case and converted to zero, which | |
262 | * is later treated as a "don't care" value. | |
263 | */ | |
264 | static inline int parse_lineno(const char *str, unsigned int *val) | |
265 | { | |
266 | char *end = NULL; | |
267 | BUG_ON(str == NULL); | |
268 | if (*str == '\0') { | |
269 | *val = 0; | |
270 | return 0; | |
271 | } | |
272 | *val = simple_strtoul(str, &end, 10); | |
273 | if (end == NULL || end == str || *end != '\0') { | |
274 | pr_err("bad line-number: %s\n", str); | |
275 | return -EINVAL; | |
276 | } | |
277 | return 0; | |
278 | } | |
279 | ||
280 | static int check_set(const char **dest, char *src, char *name) | |
281 | { | |
282 | int rc = 0; | |
283 | ||
284 | if (*dest) { | |
285 | rc = -EINVAL; | |
286 | pr_err("match-spec:%s val:%s overridden by %s\n", | |
287 | name, *dest, src); | |
288 | } | |
289 | *dest = src; | |
290 | return rc; | |
291 | } | |
292 | ||
293 | /* | |
294 | * Parse words[] as a ddebug query specification, which is a series | |
295 | * of (keyword, value) pairs chosen from these possibilities: | |
296 | * | |
297 | * func <function-name> | |
298 | * file <full-pathname> | |
299 | * file <base-filename> | |
300 | * module <module-name> | |
301 | * format <escaped-string-to-find-in-format> | |
302 | * line <lineno> | |
303 | * line <first-lineno>-<last-lineno> // where either may be empty | |
304 | * | |
305 | * Only 1 of each type is allowed. | |
306 | * Returns 0 on success, <0 on error. | |
307 | */ | |
308 | static int ddebug_parse_query(char *words[], int nwords, | |
309 | struct ddebug_query *query, const char *modname) | |
310 | { | |
311 | unsigned int i; | |
312 | int rc; | |
313 | ||
314 | /* check we have an even number of words */ | |
315 | if (nwords % 2 != 0) { | |
316 | pr_err("expecting pairs of match-spec <value>\n"); | |
317 | return -EINVAL; | |
318 | } | |
319 | memset(query, 0, sizeof(*query)); | |
320 | ||
321 | if (modname) | |
322 | /* support $modname.dyndbg=<multiple queries> */ | |
323 | query->module = modname; | |
324 | ||
325 | for (i = 0; i < nwords; i += 2) { | |
326 | if (!strcmp(words[i], "func")) { | |
327 | rc = check_set(&query->function, words[i+1], "func"); | |
328 | } else if (!strcmp(words[i], "file")) { | |
329 | rc = check_set(&query->filename, words[i+1], "file"); | |
330 | } else if (!strcmp(words[i], "module")) { | |
331 | rc = check_set(&query->module, words[i+1], "module"); | |
332 | } else if (!strcmp(words[i], "format")) { | |
333 | string_unescape_inplace(words[i+1], UNESCAPE_SPACE | | |
334 | UNESCAPE_OCTAL | | |
335 | UNESCAPE_SPECIAL); | |
336 | rc = check_set(&query->format, words[i+1], "format"); | |
337 | } else if (!strcmp(words[i], "line")) { | |
338 | char *first = words[i+1]; | |
339 | char *last = strchr(first, '-'); | |
340 | if (query->first_lineno || query->last_lineno) { | |
341 | pr_err("match-spec: line used 2x\n"); | |
342 | return -EINVAL; | |
343 | } | |
344 | if (last) | |
345 | *last++ = '\0'; | |
346 | if (parse_lineno(first, &query->first_lineno) < 0) { | |
347 | pr_err("line-number is <0\n"); | |
348 | return -EINVAL; | |
349 | } | |
350 | if (last) { | |
351 | /* range <first>-<last> */ | |
352 | if (parse_lineno(last, &query->last_lineno) | |
353 | < query->first_lineno) { | |
354 | pr_err("last-line:%d < 1st-line:%d\n", | |
355 | query->last_lineno, | |
356 | query->first_lineno); | |
357 | return -EINVAL; | |
358 | } | |
359 | } else { | |
360 | query->last_lineno = query->first_lineno; | |
361 | } | |
362 | } else { | |
363 | pr_err("unknown keyword \"%s\"\n", words[i]); | |
364 | return -EINVAL; | |
365 | } | |
366 | if (rc) | |
367 | return rc; | |
368 | } | |
369 | vpr_info_dq(query, "parsed"); | |
370 | return 0; | |
371 | } | |
372 | ||
373 | /* | |
374 | * Parse `str' as a flags specification, format [-+=][p]+. | |
375 | * Sets up *maskp and *flagsp to be used when changing the | |
376 | * flags fields of matched _ddebug's. Returns 0 on success | |
377 | * or <0 on error. | |
378 | */ | |
379 | static int ddebug_parse_flags(const char *str, unsigned int *flagsp, | |
380 | unsigned int *maskp) | |
381 | { | |
382 | unsigned flags = 0; | |
383 | int op = '=', i; | |
384 | ||
385 | switch (*str) { | |
386 | case '+': | |
387 | case '-': | |
388 | case '=': | |
389 | op = *str++; | |
390 | break; | |
391 | default: | |
392 | pr_err("bad flag-op %c, at start of %s\n", *str, str); | |
393 | return -EINVAL; | |
394 | } | |
395 | vpr_info("op='%c'\n", op); | |
396 | ||
397 | for (; *str ; ++str) { | |
398 | for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) { | |
399 | if (*str == opt_array[i].opt_char) { | |
400 | flags |= opt_array[i].flag; | |
401 | break; | |
402 | } | |
403 | } | |
404 | if (i < 0) { | |
405 | pr_err("unknown flag '%c' in \"%s\"\n", *str, str); | |
406 | return -EINVAL; | |
407 | } | |
408 | } | |
409 | vpr_info("flags=0x%x\n", flags); | |
410 | ||
411 | /* calculate final *flagsp, *maskp according to mask and op */ | |
412 | switch (op) { | |
413 | case '=': | |
414 | *maskp = 0; | |
415 | *flagsp = flags; | |
416 | break; | |
417 | case '+': | |
418 | *maskp = ~0U; | |
419 | *flagsp = flags; | |
420 | break; | |
421 | case '-': | |
422 | *maskp = ~flags; | |
423 | *flagsp = 0; | |
424 | break; | |
425 | } | |
426 | vpr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp); | |
427 | return 0; | |
428 | } | |
429 | ||
430 | static int ddebug_exec_query(char *query_string, const char *modname) | |
431 | { | |
432 | unsigned int flags = 0, mask = 0; | |
433 | struct ddebug_query query; | |
434 | #define MAXWORDS 9 | |
435 | int nwords, nfound; | |
436 | char *words[MAXWORDS]; | |
437 | ||
438 | nwords = ddebug_tokenize(query_string, words, MAXWORDS); | |
439 | if (nwords <= 0) { | |
440 | pr_err("tokenize failed\n"); | |
441 | return -EINVAL; | |
442 | } | |
443 | /* check flags 1st (last arg) so query is pairs of spec,val */ | |
444 | if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) { | |
445 | pr_err("flags parse failed\n"); | |
446 | return -EINVAL; | |
447 | } | |
448 | if (ddebug_parse_query(words, nwords-1, &query, modname)) { | |
449 | pr_err("query parse failed\n"); | |
450 | return -EINVAL; | |
451 | } | |
452 | /* actually go and implement the change */ | |
453 | nfound = ddebug_change(&query, flags, mask); | |
454 | vpr_info_dq(&query, nfound ? "applied" : "no-match"); | |
455 | ||
456 | return nfound; | |
457 | } | |
458 | ||
459 | /* handle multiple queries in query string, continue on error, return | |
460 | last error or number of matching callsites. Module name is either | |
461 | in param (for boot arg) or perhaps in query string. | |
462 | */ | |
463 | static int ddebug_exec_queries(char *query, const char *modname) | |
464 | { | |
465 | char *split; | |
466 | int i, errs = 0, exitcode = 0, rc, nfound = 0; | |
467 | ||
468 | for (i = 0; query; query = split) { | |
469 | split = strpbrk(query, ";\n"); | |
470 | if (split) | |
471 | *split++ = '\0'; | |
472 | ||
473 | query = skip_spaces(query); | |
474 | if (!query || !*query || *query == '#') | |
475 | continue; | |
476 | ||
477 | vpr_info("query %d: \"%s\"\n", i, query); | |
478 | ||
479 | rc = ddebug_exec_query(query, modname); | |
480 | if (rc < 0) { | |
481 | errs++; | |
482 | exitcode = rc; | |
483 | } else { | |
484 | nfound += rc; | |
485 | } | |
486 | i++; | |
487 | } | |
488 | vpr_info("processed %d queries, with %d matches, %d errs\n", | |
489 | i, nfound, errs); | |
490 | ||
491 | if (exitcode) | |
492 | return exitcode; | |
493 | return nfound; | |
494 | } | |
495 | ||
496 | #define PREFIX_SIZE 64 | |
497 | ||
498 | static int remaining(int wrote) | |
499 | { | |
500 | if (PREFIX_SIZE - wrote > 0) | |
501 | return PREFIX_SIZE - wrote; | |
502 | return 0; | |
503 | } | |
504 | ||
505 | static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf) | |
506 | { | |
507 | int pos_after_tid; | |
508 | int pos = 0; | |
509 | ||
510 | *buf = '\0'; | |
511 | ||
512 | if (desc->flags & _DPRINTK_FLAGS_INCL_TID) { | |
513 | if (in_interrupt()) | |
514 | pos += snprintf(buf + pos, remaining(pos), "<intr> "); | |
515 | else | |
516 | pos += snprintf(buf + pos, remaining(pos), "[%d] ", | |
517 | task_pid_vnr(current)); | |
518 | } | |
519 | pos_after_tid = pos; | |
520 | if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME) | |
521 | pos += snprintf(buf + pos, remaining(pos), "%s:", | |
522 | desc->modname); | |
523 | if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME) | |
524 | pos += snprintf(buf + pos, remaining(pos), "%s:", | |
525 | desc->function); | |
526 | if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO) | |
527 | pos += snprintf(buf + pos, remaining(pos), "%d:", | |
528 | desc->lineno); | |
529 | if (pos - pos_after_tid) | |
530 | pos += snprintf(buf + pos, remaining(pos), " "); | |
531 | if (pos >= PREFIX_SIZE) | |
532 | buf[PREFIX_SIZE - 1] = '\0'; | |
533 | ||
534 | return buf; | |
535 | } | |
536 | ||
537 | int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...) | |
538 | { | |
539 | va_list args; | |
540 | int res; | |
541 | struct va_format vaf; | |
542 | char buf[PREFIX_SIZE]; | |
543 | ||
544 | BUG_ON(!descriptor); | |
545 | BUG_ON(!fmt); | |
546 | ||
547 | va_start(args, fmt); | |
548 | ||
549 | vaf.fmt = fmt; | |
550 | vaf.va = &args; | |
551 | ||
552 | res = printk(KERN_DEBUG "%s%pV", | |
553 | dynamic_emit_prefix(descriptor, buf), &vaf); | |
554 | ||
555 | va_end(args); | |
556 | ||
557 | return res; | |
558 | } | |
559 | EXPORT_SYMBOL(__dynamic_pr_debug); | |
560 | ||
561 | int __dynamic_dev_dbg(struct _ddebug *descriptor, | |
562 | const struct device *dev, const char *fmt, ...) | |
563 | { | |
564 | struct va_format vaf; | |
565 | va_list args; | |
566 | int res; | |
567 | ||
568 | BUG_ON(!descriptor); | |
569 | BUG_ON(!fmt); | |
570 | ||
571 | va_start(args, fmt); | |
572 | ||
573 | vaf.fmt = fmt; | |
574 | vaf.va = &args; | |
575 | ||
576 | if (!dev) { | |
577 | res = printk(KERN_DEBUG "(NULL device *): %pV", &vaf); | |
578 | } else { | |
579 | char buf[PREFIX_SIZE]; | |
580 | ||
581 | res = dev_printk_emit(7, dev, "%s%s %s: %pV", | |
582 | dynamic_emit_prefix(descriptor, buf), | |
583 | dev_driver_string(dev), dev_name(dev), | |
584 | &vaf); | |
585 | } | |
586 | ||
587 | va_end(args); | |
588 | ||
589 | return res; | |
590 | } | |
591 | EXPORT_SYMBOL(__dynamic_dev_dbg); | |
592 | ||
593 | #ifdef CONFIG_NET | |
594 | ||
595 | int __dynamic_netdev_dbg(struct _ddebug *descriptor, | |
596 | const struct net_device *dev, const char *fmt, ...) | |
597 | { | |
598 | struct va_format vaf; | |
599 | va_list args; | |
600 | int res; | |
601 | ||
602 | BUG_ON(!descriptor); | |
603 | BUG_ON(!fmt); | |
604 | ||
605 | va_start(args, fmt); | |
606 | ||
607 | vaf.fmt = fmt; | |
608 | vaf.va = &args; | |
609 | ||
610 | if (dev && dev->dev.parent) { | |
611 | char buf[PREFIX_SIZE]; | |
612 | ||
613 | res = dev_printk_emit(7, dev->dev.parent, | |
614 | "%s%s %s %s: %pV", | |
615 | dynamic_emit_prefix(descriptor, buf), | |
616 | dev_driver_string(dev->dev.parent), | |
617 | dev_name(dev->dev.parent), | |
618 | netdev_name(dev), &vaf); | |
619 | } else if (dev) { | |
620 | res = printk(KERN_DEBUG "%s: %pV", netdev_name(dev), &vaf); | |
621 | } else { | |
622 | res = printk(KERN_DEBUG "(NULL net_device): %pV", &vaf); | |
623 | } | |
624 | ||
625 | va_end(args); | |
626 | ||
627 | return res; | |
628 | } | |
629 | EXPORT_SYMBOL(__dynamic_netdev_dbg); | |
630 | ||
631 | #endif | |
632 | ||
633 | #define DDEBUG_STRING_SIZE 1024 | |
634 | static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE]; | |
635 | ||
636 | static __init int ddebug_setup_query(char *str) | |
637 | { | |
638 | if (strlen(str) >= DDEBUG_STRING_SIZE) { | |
639 | pr_warn("ddebug boot param string too large\n"); | |
640 | return 0; | |
641 | } | |
642 | strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE); | |
643 | return 1; | |
644 | } | |
645 | ||
646 | __setup("ddebug_query=", ddebug_setup_query); | |
647 | ||
648 | /* | |
649 | * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the | |
650 | * command text from userspace, parses and executes it. | |
651 | */ | |
652 | #define USER_BUF_PAGE 4096 | |
653 | static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, | |
654 | size_t len, loff_t *offp) | |
655 | { | |
656 | char *tmpbuf; | |
657 | int ret; | |
658 | ||
659 | if (len == 0) | |
660 | return 0; | |
661 | if (len > USER_BUF_PAGE - 1) { | |
662 | pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE); | |
663 | return -E2BIG; | |
664 | } | |
665 | tmpbuf = kmalloc(len + 1, GFP_KERNEL); | |
666 | if (!tmpbuf) | |
667 | return -ENOMEM; | |
668 | if (copy_from_user(tmpbuf, ubuf, len)) { | |
669 | kfree(tmpbuf); | |
670 | return -EFAULT; | |
671 | } | |
672 | tmpbuf[len] = '\0'; | |
673 | vpr_info("read %d bytes from userspace\n", (int)len); | |
674 | ||
675 | ret = ddebug_exec_queries(tmpbuf, NULL); | |
676 | kfree(tmpbuf); | |
677 | if (ret < 0) | |
678 | return ret; | |
679 | ||
680 | *offp += len; | |
681 | return len; | |
682 | } | |
683 | ||
684 | /* | |
685 | * Set the iterator to point to the first _ddebug object | |
686 | * and return a pointer to that first object. Returns | |
687 | * NULL if there are no _ddebugs at all. | |
688 | */ | |
689 | static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter) | |
690 | { | |
691 | if (list_empty(&ddebug_tables)) { | |
692 | iter->table = NULL; | |
693 | iter->idx = 0; | |
694 | return NULL; | |
695 | } | |
696 | iter->table = list_entry(ddebug_tables.next, | |
697 | struct ddebug_table, link); | |
698 | iter->idx = 0; | |
699 | return &iter->table->ddebugs[iter->idx]; | |
700 | } | |
701 | ||
702 | /* | |
703 | * Advance the iterator to point to the next _ddebug | |
704 | * object from the one the iterator currently points at, | |
705 | * and returns a pointer to the new _ddebug. Returns | |
706 | * NULL if the iterator has seen all the _ddebugs. | |
707 | */ | |
708 | static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter) | |
709 | { | |
710 | if (iter->table == NULL) | |
711 | return NULL; | |
712 | if (++iter->idx == iter->table->num_ddebugs) { | |
713 | /* iterate to next table */ | |
714 | iter->idx = 0; | |
715 | if (list_is_last(&iter->table->link, &ddebug_tables)) { | |
716 | iter->table = NULL; | |
717 | return NULL; | |
718 | } | |
719 | iter->table = list_entry(iter->table->link.next, | |
720 | struct ddebug_table, link); | |
721 | } | |
722 | return &iter->table->ddebugs[iter->idx]; | |
723 | } | |
724 | ||
725 | /* | |
726 | * Seq_ops start method. Called at the start of every | |
727 | * read() call from userspace. Takes the ddebug_lock and | |
728 | * seeks the seq_file's iterator to the given position. | |
729 | */ | |
730 | static void *ddebug_proc_start(struct seq_file *m, loff_t *pos) | |
731 | { | |
732 | struct ddebug_iter *iter = m->private; | |
733 | struct _ddebug *dp; | |
734 | int n = *pos; | |
735 | ||
736 | vpr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos); | |
737 | ||
738 | mutex_lock(&ddebug_lock); | |
739 | ||
740 | if (!n) | |
741 | return SEQ_START_TOKEN; | |
742 | if (n < 0) | |
743 | return NULL; | |
744 | dp = ddebug_iter_first(iter); | |
745 | while (dp != NULL && --n > 0) | |
746 | dp = ddebug_iter_next(iter); | |
747 | return dp; | |
748 | } | |
749 | ||
750 | /* | |
751 | * Seq_ops next method. Called several times within a read() | |
752 | * call from userspace, with ddebug_lock held. Walks to the | |
753 | * next _ddebug object with a special case for the header line. | |
754 | */ | |
755 | static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos) | |
756 | { | |
757 | struct ddebug_iter *iter = m->private; | |
758 | struct _ddebug *dp; | |
759 | ||
760 | vpr_info("called m=%p p=%p *pos=%lld\n", | |
761 | m, p, (unsigned long long)*pos); | |
762 | ||
763 | if (p == SEQ_START_TOKEN) | |
764 | dp = ddebug_iter_first(iter); | |
765 | else | |
766 | dp = ddebug_iter_next(iter); | |
767 | ++*pos; | |
768 | return dp; | |
769 | } | |
770 | ||
771 | /* | |
772 | * Seq_ops show method. Called several times within a read() | |
773 | * call from userspace, with ddebug_lock held. Formats the | |
774 | * current _ddebug as a single human-readable line, with a | |
775 | * special case for the header line. | |
776 | */ | |
777 | static int ddebug_proc_show(struct seq_file *m, void *p) | |
778 | { | |
779 | struct ddebug_iter *iter = m->private; | |
780 | struct _ddebug *dp = p; | |
781 | char flagsbuf[10]; | |
782 | ||
783 | vpr_info("called m=%p p=%p\n", m, p); | |
784 | ||
785 | if (p == SEQ_START_TOKEN) { | |
786 | seq_puts(m, | |
787 | "# filename:lineno [module]function flags format\n"); | |
788 | return 0; | |
789 | } | |
790 | ||
791 | seq_printf(m, "%s:%u [%s]%s =%s \"", | |
792 | trim_prefix(dp->filename), dp->lineno, | |
793 | iter->table->mod_name, dp->function, | |
794 | ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf))); | |
795 | seq_escape(m, dp->format, "\t\r\n\""); | |
796 | seq_puts(m, "\"\n"); | |
797 | ||
798 | return 0; | |
799 | } | |
800 | ||
801 | /* | |
802 | * Seq_ops stop method. Called at the end of each read() | |
803 | * call from userspace. Drops ddebug_lock. | |
804 | */ | |
805 | static void ddebug_proc_stop(struct seq_file *m, void *p) | |
806 | { | |
807 | vpr_info("called m=%p p=%p\n", m, p); | |
808 | mutex_unlock(&ddebug_lock); | |
809 | } | |
810 | ||
811 | static const struct seq_operations ddebug_proc_seqops = { | |
812 | .start = ddebug_proc_start, | |
813 | .next = ddebug_proc_next, | |
814 | .show = ddebug_proc_show, | |
815 | .stop = ddebug_proc_stop | |
816 | }; | |
817 | ||
818 | /* | |
819 | * File_ops->open method for <debugfs>/dynamic_debug/control. Does | |
820 | * the seq_file setup dance, and also creates an iterator to walk the | |
821 | * _ddebugs. Note that we create a seq_file always, even for O_WRONLY | |
822 | * files where it's not needed, as doing so simplifies the ->release | |
823 | * method. | |
824 | */ | |
825 | static int ddebug_proc_open(struct inode *inode, struct file *file) | |
826 | { | |
827 | struct ddebug_iter *iter; | |
828 | int err; | |
829 | ||
830 | vpr_info("called\n"); | |
831 | ||
832 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
833 | if (iter == NULL) | |
834 | return -ENOMEM; | |
835 | ||
836 | err = seq_open(file, &ddebug_proc_seqops); | |
837 | if (err) { | |
838 | kfree(iter); | |
839 | return err; | |
840 | } | |
841 | ((struct seq_file *)file->private_data)->private = iter; | |
842 | return 0; | |
843 | } | |
844 | ||
845 | static const struct file_operations ddebug_proc_fops = { | |
846 | .owner = THIS_MODULE, | |
847 | .open = ddebug_proc_open, | |
848 | .read = seq_read, | |
849 | .llseek = seq_lseek, | |
850 | .release = seq_release_private, | |
851 | .write = ddebug_proc_write | |
852 | }; | |
853 | ||
854 | /* | |
855 | * Allocate a new ddebug_table for the given module | |
856 | * and add it to the global list. | |
857 | */ | |
858 | int ddebug_add_module(struct _ddebug *tab, unsigned int n, | |
859 | const char *name) | |
860 | { | |
861 | struct ddebug_table *dt; | |
862 | char *new_name; | |
863 | ||
864 | dt = kzalloc(sizeof(*dt), GFP_KERNEL); | |
865 | if (dt == NULL) | |
866 | return -ENOMEM; | |
867 | new_name = kstrdup(name, GFP_KERNEL); | |
868 | if (new_name == NULL) { | |
869 | kfree(dt); | |
870 | return -ENOMEM; | |
871 | } | |
872 | dt->mod_name = new_name; | |
873 | dt->num_ddebugs = n; | |
874 | dt->ddebugs = tab; | |
875 | ||
876 | mutex_lock(&ddebug_lock); | |
877 | list_add_tail(&dt->link, &ddebug_tables); | |
878 | mutex_unlock(&ddebug_lock); | |
879 | ||
880 | vpr_info("%u debug prints in module %s\n", n, dt->mod_name); | |
881 | return 0; | |
882 | } | |
883 | EXPORT_SYMBOL_GPL(ddebug_add_module); | |
884 | ||
885 | /* helper for ddebug_dyndbg_(boot|module)_param_cb */ | |
886 | static int ddebug_dyndbg_param_cb(char *param, char *val, | |
887 | const char *modname, int on_err) | |
888 | { | |
889 | char *sep; | |
890 | ||
891 | sep = strchr(param, '.'); | |
892 | if (sep) { | |
893 | /* needed only for ddebug_dyndbg_boot_param_cb */ | |
894 | *sep = '\0'; | |
895 | modname = param; | |
896 | param = sep + 1; | |
897 | } | |
898 | if (strcmp(param, "dyndbg")) | |
899 | return on_err; /* determined by caller */ | |
900 | ||
901 | ddebug_exec_queries((val ? val : "+p"), modname); | |
902 | ||
903 | return 0; /* query failure shouldnt stop module load */ | |
904 | } | |
905 | ||
906 | /* handle both dyndbg and $module.dyndbg params at boot */ | |
907 | static int ddebug_dyndbg_boot_param_cb(char *param, char *val, | |
908 | const char *unused) | |
909 | { | |
910 | vpr_info("%s=\"%s\"\n", param, val); | |
911 | return ddebug_dyndbg_param_cb(param, val, NULL, 0); | |
912 | } | |
913 | ||
914 | /* | |
915 | * modprobe foo finds foo.params in boot-args, strips "foo.", and | |
916 | * passes them to load_module(). This callback gets unknown params, | |
917 | * processes dyndbg params, rejects others. | |
918 | */ | |
919 | int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module) | |
920 | { | |
921 | vpr_info("module: %s %s=\"%s\"\n", module, param, val); | |
922 | return ddebug_dyndbg_param_cb(param, val, module, -ENOENT); | |
923 | } | |
924 | ||
925 | static void ddebug_table_free(struct ddebug_table *dt) | |
926 | { | |
927 | list_del_init(&dt->link); | |
928 | kfree(dt->mod_name); | |
929 | kfree(dt); | |
930 | } | |
931 | ||
932 | /* | |
933 | * Called in response to a module being unloaded. Removes | |
934 | * any ddebug_table's which point at the module. | |
935 | */ | |
936 | int ddebug_remove_module(const char *mod_name) | |
937 | { | |
938 | struct ddebug_table *dt, *nextdt; | |
939 | int ret = -ENOENT; | |
940 | ||
941 | vpr_info("removing module \"%s\"\n", mod_name); | |
942 | ||
943 | mutex_lock(&ddebug_lock); | |
944 | list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) { | |
945 | if (!strcmp(dt->mod_name, mod_name)) { | |
946 | ddebug_table_free(dt); | |
947 | ret = 0; | |
948 | } | |
949 | } | |
950 | mutex_unlock(&ddebug_lock); | |
951 | return ret; | |
952 | } | |
953 | EXPORT_SYMBOL_GPL(ddebug_remove_module); | |
954 | ||
955 | static void ddebug_remove_all_tables(void) | |
956 | { | |
957 | mutex_lock(&ddebug_lock); | |
958 | while (!list_empty(&ddebug_tables)) { | |
959 | struct ddebug_table *dt = list_entry(ddebug_tables.next, | |
960 | struct ddebug_table, | |
961 | link); | |
962 | ddebug_table_free(dt); | |
963 | } | |
964 | mutex_unlock(&ddebug_lock); | |
965 | } | |
966 | ||
967 | static __initdata int ddebug_init_success; | |
968 | ||
969 | static int __init dynamic_debug_init_debugfs(void) | |
970 | { | |
971 | struct dentry *dir, *file; | |
972 | ||
973 | if (!ddebug_init_success) | |
974 | return -ENODEV; | |
975 | ||
976 | dir = debugfs_create_dir("dynamic_debug", NULL); | |
977 | if (!dir) | |
978 | return -ENOMEM; | |
979 | file = debugfs_create_file("control", 0644, dir, NULL, | |
980 | &ddebug_proc_fops); | |
981 | if (!file) { | |
982 | debugfs_remove(dir); | |
983 | return -ENOMEM; | |
984 | } | |
985 | return 0; | |
986 | } | |
987 | ||
988 | static int __init dynamic_debug_init(void) | |
989 | { | |
990 | struct _ddebug *iter, *iter_start; | |
991 | const char *modname = NULL; | |
992 | char *cmdline; | |
993 | int ret = 0; | |
994 | int n = 0, entries = 0, modct = 0; | |
995 | int verbose_bytes = 0; | |
996 | ||
997 | if (__start___verbose == __stop___verbose) { | |
998 | pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n"); | |
999 | return 1; | |
1000 | } | |
1001 | iter = __start___verbose; | |
1002 | modname = iter->modname; | |
1003 | iter_start = iter; | |
1004 | for (; iter < __stop___verbose; iter++) { | |
1005 | entries++; | |
1006 | verbose_bytes += strlen(iter->modname) + strlen(iter->function) | |
1007 | + strlen(iter->filename) + strlen(iter->format); | |
1008 | ||
1009 | if (strcmp(modname, iter->modname)) { | |
1010 | modct++; | |
1011 | ret = ddebug_add_module(iter_start, n, modname); | |
1012 | if (ret) | |
1013 | goto out_err; | |
1014 | n = 0; | |
1015 | modname = iter->modname; | |
1016 | iter_start = iter; | |
1017 | } | |
1018 | n++; | |
1019 | } | |
1020 | ret = ddebug_add_module(iter_start, n, modname); | |
1021 | if (ret) | |
1022 | goto out_err; | |
1023 | ||
1024 | ddebug_init_success = 1; | |
1025 | vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in (readonly) verbose section\n", | |
1026 | modct, entries, (int)(modct * sizeof(struct ddebug_table)), | |
1027 | verbose_bytes + (int)(__stop___verbose - __start___verbose)); | |
1028 | ||
1029 | /* apply ddebug_query boot param, dont unload tables on err */ | |
1030 | if (ddebug_setup_string[0] != '\0') { | |
1031 | pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n"); | |
1032 | ret = ddebug_exec_queries(ddebug_setup_string, NULL); | |
1033 | if (ret < 0) | |
1034 | pr_warn("Invalid ddebug boot param %s\n", | |
1035 | ddebug_setup_string); | |
1036 | else | |
1037 | pr_info("%d changes by ddebug_query\n", ret); | |
1038 | } | |
1039 | /* now that ddebug tables are loaded, process all boot args | |
1040 | * again to find and activate queries given in dyndbg params. | |
1041 | * While this has already been done for known boot params, it | |
1042 | * ignored the unknown ones (dyndbg in particular). Reusing | |
1043 | * parse_args avoids ad-hoc parsing. This will also attempt | |
1044 | * to activate queries for not-yet-loaded modules, which is | |
1045 | * slightly noisy if verbose, but harmless. | |
1046 | */ | |
1047 | cmdline = kstrdup(saved_command_line, GFP_KERNEL); | |
1048 | parse_args("dyndbg params", cmdline, NULL, | |
1049 | 0, 0, 0, &ddebug_dyndbg_boot_param_cb); | |
1050 | kfree(cmdline); | |
1051 | return 0; | |
1052 | ||
1053 | out_err: | |
1054 | ddebug_remove_all_tables(); | |
1055 | return 0; | |
1056 | } | |
1057 | /* Allow early initialization for boot messages via boot param */ | |
1058 | early_initcall(dynamic_debug_init); | |
1059 | ||
1060 | /* Debugfs setup must be done later */ | |
1061 | fs_initcall(dynamic_debug_init_debugfs); |