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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
40extern struct _ddebug __start___verbose[];
41extern struct _ddebug __stop___verbose[];
42
43struct ddebug_table {
44 struct list_head link;
45 const char *mod_name;
46 unsigned int num_ddebugs;
47 struct _ddebug *ddebugs;
48};
49
50struct 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
58struct ddebug_iter {
59 struct ddebug_table *table;
60 unsigned int idx;
61};
62
63static DEFINE_MUTEX(ddebug_lock);
64static LIST_HEAD(ddebug_tables);
65static int verbose;
66module_param(verbose, int, 0644);
67
68/* Return the path relative to source root */
69static 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
79static 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 */
89static 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, ...) \
107do { \
108 if (verbose) \
109 pr_info(fmt, ##__VA_ARGS__); \
110} while (0)
111
112static 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 */
138static 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 */
220static 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 */
276static 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
290static 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 */
318static 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 */
389static 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
440static 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*/
473static 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
508static int remaining(int wrote)
509{
510 if (PREFIX_SIZE - wrote > 0)
511 return PREFIX_SIZE - wrote;
512 return 0;
513}
514
515static 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
547void __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}
565EXPORT_SYMBOL(__dynamic_pr_debug);
566
567void __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}
594EXPORT_SYMBOL(__dynamic_dev_dbg);
595
596#ifdef CONFIG_NET
597
598void __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}
631EXPORT_SYMBOL(__dynamic_netdev_dbg);
632
633#endif
634
635#define DDEBUG_STRING_SIZE 1024
636static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
637
638static __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
655static 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 */
686static 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 */
705static 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 */
727static 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 */
752static 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 */
774static 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 */
802static 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
808static 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 */
822static 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
829static 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 */
842int 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}
867EXPORT_SYMBOL_GPL(ddebug_add_module);
868
869/* helper for ddebug_dyndbg_(boot|module)_param_cb */
870static 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 */
891static 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 */
903int 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
909static 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 */
920int 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}
937EXPORT_SYMBOL_GPL(ddebug_remove_module);
938
939static 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
951static __initdata int ddebug_init_success;
952
953static 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
972static 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
1037out_err:
1038 ddebug_remove_all_tables();
1039 return 0;
1040}
1041/* Allow early initialization for boot messages via boot param */
1042early_initcall(dynamic_debug_init);
1043
1044/* Debugfs setup must be done later */
1045fs_initcall(dynamic_debug_init_debugfs);
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#include <rdma/ib_verbs.h>
41
42extern struct _ddebug __start___verbose[];
43extern struct _ddebug __stop___verbose[];
44
45struct ddebug_table {
46 struct list_head link;
47 const char *mod_name;
48 unsigned int num_ddebugs;
49 struct _ddebug *ddebugs;
50};
51
52struct ddebug_query {
53 const char *filename;
54 const char *module;
55 const char *function;
56 const char *format;
57 unsigned int first_lineno, last_lineno;
58};
59
60struct ddebug_iter {
61 struct ddebug_table *table;
62 unsigned int idx;
63};
64
65static DEFINE_MUTEX(ddebug_lock);
66static LIST_HEAD(ddebug_tables);
67static int verbose;
68module_param(verbose, int, 0644);
69
70/* Return the path relative to source root */
71static inline const char *trim_prefix(const char *path)
72{
73 int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
74
75 if (strncmp(path, __FILE__, skip))
76 skip = 0; /* prefix mismatch, don't skip */
77
78 return path + skip;
79}
80
81static struct { unsigned flag:8; char opt_char; } opt_array[] = {
82 { _DPRINTK_FLAGS_PRINT, 'p' },
83 { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
84 { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
85 { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
86 { _DPRINTK_FLAGS_INCL_TID, 't' },
87 { _DPRINTK_FLAGS_NONE, '_' },
88};
89
90/* format a string into buf[] which describes the _ddebug's flags */
91static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
92 size_t maxlen)
93{
94 char *p = buf;
95 int i;
96
97 BUG_ON(maxlen < 6);
98 for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
99 if (dp->flags & opt_array[i].flag)
100 *p++ = opt_array[i].opt_char;
101 if (p == buf)
102 *p++ = '_';
103 *p = '\0';
104
105 return buf;
106}
107
108#define vpr_info(fmt, ...) \
109do { \
110 if (verbose) \
111 pr_info(fmt, ##__VA_ARGS__); \
112} while (0)
113
114static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
115{
116 /* trim any trailing newlines */
117 int fmtlen = 0;
118
119 if (query->format) {
120 fmtlen = strlen(query->format);
121 while (fmtlen && query->format[fmtlen - 1] == '\n')
122 fmtlen--;
123 }
124
125 vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n",
126 msg,
127 query->function ? query->function : "",
128 query->filename ? query->filename : "",
129 query->module ? query->module : "",
130 fmtlen, query->format ? query->format : "",
131 query->first_lineno, query->last_lineno);
132}
133
134/*
135 * Search the tables for _ddebug's which match the given `query' and
136 * apply the `flags' and `mask' to them. Returns number of matching
137 * callsites, normally the same as number of changes. If verbose,
138 * logs the changes. Takes ddebug_lock.
139 */
140static int ddebug_change(const struct ddebug_query *query,
141 unsigned int flags, unsigned int mask)
142{
143 int i;
144 struct ddebug_table *dt;
145 unsigned int newflags;
146 unsigned int nfound = 0;
147 char flagbuf[10];
148
149 /* search for matching ddebugs */
150 mutex_lock(&ddebug_lock);
151 list_for_each_entry(dt, &ddebug_tables, link) {
152
153 /* match against the module name */
154 if (query->module &&
155 !match_wildcard(query->module, dt->mod_name))
156 continue;
157
158 for (i = 0; i < dt->num_ddebugs; i++) {
159 struct _ddebug *dp = &dt->ddebugs[i];
160
161 /* match against the source filename */
162 if (query->filename &&
163 !match_wildcard(query->filename, dp->filename) &&
164 !match_wildcard(query->filename,
165 kbasename(dp->filename)) &&
166 !match_wildcard(query->filename,
167 trim_prefix(dp->filename)))
168 continue;
169
170 /* match against the function */
171 if (query->function &&
172 !match_wildcard(query->function, dp->function))
173 continue;
174
175 /* match against the format */
176 if (query->format &&
177 !strstr(dp->format, query->format))
178 continue;
179
180 /* match against the line number range */
181 if (query->first_lineno &&
182 dp->lineno < query->first_lineno)
183 continue;
184 if (query->last_lineno &&
185 dp->lineno > query->last_lineno)
186 continue;
187
188 nfound++;
189
190 newflags = (dp->flags & mask) | flags;
191 if (newflags == dp->flags)
192 continue;
193#ifdef CONFIG_JUMP_LABEL
194 if (dp->flags & _DPRINTK_FLAGS_PRINT) {
195 if (!(flags & _DPRINTK_FLAGS_PRINT))
196 static_branch_disable(&dp->key.dd_key_true);
197 } else if (flags & _DPRINTK_FLAGS_PRINT)
198 static_branch_enable(&dp->key.dd_key_true);
199#endif
200 dp->flags = newflags;
201 vpr_info("changed %s:%d [%s]%s =%s\n",
202 trim_prefix(dp->filename), dp->lineno,
203 dt->mod_name, dp->function,
204 ddebug_describe_flags(dp, flagbuf,
205 sizeof(flagbuf)));
206 }
207 }
208 mutex_unlock(&ddebug_lock);
209
210 if (!nfound && verbose)
211 pr_info("no matches for query\n");
212
213 return nfound;
214}
215
216/*
217 * Split the buffer `buf' into space-separated words.
218 * Handles simple " and ' quoting, i.e. without nested,
219 * embedded or escaped \". Return the number of words
220 * or <0 on error.
221 */
222static int ddebug_tokenize(char *buf, char *words[], int maxwords)
223{
224 int nwords = 0;
225
226 while (*buf) {
227 char *end;
228
229 /* Skip leading whitespace */
230 buf = skip_spaces(buf);
231 if (!*buf)
232 break; /* oh, it was trailing whitespace */
233 if (*buf == '#')
234 break; /* token starts comment, skip rest of line */
235
236 /* find `end' of word, whitespace separated or quoted */
237 if (*buf == '"' || *buf == '\'') {
238 int quote = *buf++;
239 for (end = buf; *end && *end != quote; end++)
240 ;
241 if (!*end) {
242 pr_err("unclosed quote: %s\n", buf);
243 return -EINVAL; /* unclosed quote */
244 }
245 } else {
246 for (end = buf; *end && !isspace(*end); end++)
247 ;
248 BUG_ON(end == buf);
249 }
250
251 /* `buf' is start of word, `end' is one past its end */
252 if (nwords == maxwords) {
253 pr_err("too many words, legal max <=%d\n", maxwords);
254 return -EINVAL; /* ran out of words[] before bytes */
255 }
256 if (*end)
257 *end++ = '\0'; /* terminate the word */
258 words[nwords++] = buf;
259 buf = end;
260 }
261
262 if (verbose) {
263 int i;
264 pr_info("split into words:");
265 for (i = 0; i < nwords; i++)
266 pr_cont(" \"%s\"", words[i]);
267 pr_cont("\n");
268 }
269
270 return nwords;
271}
272
273/*
274 * Parse a single line number. Note that the empty string ""
275 * is treated as a special case and converted to zero, which
276 * is later treated as a "don't care" value.
277 */
278static inline int parse_lineno(const char *str, unsigned int *val)
279{
280 BUG_ON(str == NULL);
281 if (*str == '\0') {
282 *val = 0;
283 return 0;
284 }
285 if (kstrtouint(str, 10, val) < 0) {
286 pr_err("bad line-number: %s\n", str);
287 return -EINVAL;
288 }
289 return 0;
290}
291
292static int check_set(const char **dest, char *src, char *name)
293{
294 int rc = 0;
295
296 if (*dest) {
297 rc = -EINVAL;
298 pr_err("match-spec:%s val:%s overridden by %s\n",
299 name, *dest, src);
300 }
301 *dest = src;
302 return rc;
303}
304
305/*
306 * Parse words[] as a ddebug query specification, which is a series
307 * of (keyword, value) pairs chosen from these possibilities:
308 *
309 * func <function-name>
310 * file <full-pathname>
311 * file <base-filename>
312 * module <module-name>
313 * format <escaped-string-to-find-in-format>
314 * line <lineno>
315 * line <first-lineno>-<last-lineno> // where either may be empty
316 *
317 * Only 1 of each type is allowed.
318 * Returns 0 on success, <0 on error.
319 */
320static int ddebug_parse_query(char *words[], int nwords,
321 struct ddebug_query *query, const char *modname)
322{
323 unsigned int i;
324 int rc = 0;
325
326 /* check we have an even number of words */
327 if (nwords % 2 != 0) {
328 pr_err("expecting pairs of match-spec <value>\n");
329 return -EINVAL;
330 }
331 memset(query, 0, sizeof(*query));
332
333 if (modname)
334 /* support $modname.dyndbg=<multiple queries> */
335 query->module = modname;
336
337 for (i = 0; i < nwords; i += 2) {
338 if (!strcmp(words[i], "func")) {
339 rc = check_set(&query->function, words[i+1], "func");
340 } else if (!strcmp(words[i], "file")) {
341 rc = check_set(&query->filename, words[i+1], "file");
342 } else if (!strcmp(words[i], "module")) {
343 rc = check_set(&query->module, words[i+1], "module");
344 } else if (!strcmp(words[i], "format")) {
345 string_unescape_inplace(words[i+1], UNESCAPE_SPACE |
346 UNESCAPE_OCTAL |
347 UNESCAPE_SPECIAL);
348 rc = check_set(&query->format, words[i+1], "format");
349 } else if (!strcmp(words[i], "line")) {
350 char *first = words[i+1];
351 char *last = strchr(first, '-');
352 if (query->first_lineno || query->last_lineno) {
353 pr_err("match-spec: line used 2x\n");
354 return -EINVAL;
355 }
356 if (last)
357 *last++ = '\0';
358 if (parse_lineno(first, &query->first_lineno) < 0)
359 return -EINVAL;
360 if (last) {
361 /* range <first>-<last> */
362 if (parse_lineno(last, &query->last_lineno) < 0)
363 return -EINVAL;
364
365 /* special case for last lineno not specified */
366 if (query->last_lineno == 0)
367 query->last_lineno = UINT_MAX;
368
369 if (query->last_lineno < query->first_lineno) {
370 pr_err("last-line:%d < 1st-line:%d\n",
371 query->last_lineno,
372 query->first_lineno);
373 return -EINVAL;
374 }
375 } else {
376 query->last_lineno = query->first_lineno;
377 }
378 } else {
379 pr_err("unknown keyword \"%s\"\n", words[i]);
380 return -EINVAL;
381 }
382 if (rc)
383 return rc;
384 }
385 vpr_info_dq(query, "parsed");
386 return 0;
387}
388
389/*
390 * Parse `str' as a flags specification, format [-+=][p]+.
391 * Sets up *maskp and *flagsp to be used when changing the
392 * flags fields of matched _ddebug's. Returns 0 on success
393 * or <0 on error.
394 */
395static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
396 unsigned int *maskp)
397{
398 unsigned flags = 0;
399 int op = '=', i;
400
401 switch (*str) {
402 case '+':
403 case '-':
404 case '=':
405 op = *str++;
406 break;
407 default:
408 pr_err("bad flag-op %c, at start of %s\n", *str, str);
409 return -EINVAL;
410 }
411 vpr_info("op='%c'\n", op);
412
413 for (; *str ; ++str) {
414 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
415 if (*str == opt_array[i].opt_char) {
416 flags |= opt_array[i].flag;
417 break;
418 }
419 }
420 if (i < 0) {
421 pr_err("unknown flag '%c' in \"%s\"\n", *str, str);
422 return -EINVAL;
423 }
424 }
425 vpr_info("flags=0x%x\n", flags);
426
427 /* calculate final *flagsp, *maskp according to mask and op */
428 switch (op) {
429 case '=':
430 *maskp = 0;
431 *flagsp = flags;
432 break;
433 case '+':
434 *maskp = ~0U;
435 *flagsp = flags;
436 break;
437 case '-':
438 *maskp = ~flags;
439 *flagsp = 0;
440 break;
441 }
442 vpr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp);
443 return 0;
444}
445
446static int ddebug_exec_query(char *query_string, const char *modname)
447{
448 unsigned int flags = 0, mask = 0;
449 struct ddebug_query query;
450#define MAXWORDS 9
451 int nwords, nfound;
452 char *words[MAXWORDS];
453
454 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
455 if (nwords <= 0) {
456 pr_err("tokenize failed\n");
457 return -EINVAL;
458 }
459 /* check flags 1st (last arg) so query is pairs of spec,val */
460 if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) {
461 pr_err("flags parse failed\n");
462 return -EINVAL;
463 }
464 if (ddebug_parse_query(words, nwords-1, &query, modname)) {
465 pr_err("query parse failed\n");
466 return -EINVAL;
467 }
468 /* actually go and implement the change */
469 nfound = ddebug_change(&query, flags, mask);
470 vpr_info_dq(&query, nfound ? "applied" : "no-match");
471
472 return nfound;
473}
474
475/* handle multiple queries in query string, continue on error, return
476 last error or number of matching callsites. Module name is either
477 in param (for boot arg) or perhaps in query string.
478*/
479static int ddebug_exec_queries(char *query, const char *modname)
480{
481 char *split;
482 int i, errs = 0, exitcode = 0, rc, nfound = 0;
483
484 for (i = 0; query; query = split) {
485 split = strpbrk(query, ";\n");
486 if (split)
487 *split++ = '\0';
488
489 query = skip_spaces(query);
490 if (!query || !*query || *query == '#')
491 continue;
492
493 vpr_info("query %d: \"%s\"\n", i, query);
494
495 rc = ddebug_exec_query(query, modname);
496 if (rc < 0) {
497 errs++;
498 exitcode = rc;
499 } else {
500 nfound += rc;
501 }
502 i++;
503 }
504 vpr_info("processed %d queries, with %d matches, %d errs\n",
505 i, nfound, errs);
506
507 if (exitcode)
508 return exitcode;
509 return nfound;
510}
511
512#define PREFIX_SIZE 64
513
514static int remaining(int wrote)
515{
516 if (PREFIX_SIZE - wrote > 0)
517 return PREFIX_SIZE - wrote;
518 return 0;
519}
520
521static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
522{
523 int pos_after_tid;
524 int pos = 0;
525
526 *buf = '\0';
527
528 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
529 if (in_interrupt())
530 pos += snprintf(buf + pos, remaining(pos), "<intr> ");
531 else
532 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
533 task_pid_vnr(current));
534 }
535 pos_after_tid = pos;
536 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
537 pos += snprintf(buf + pos, remaining(pos), "%s:",
538 desc->modname);
539 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
540 pos += snprintf(buf + pos, remaining(pos), "%s:",
541 desc->function);
542 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
543 pos += snprintf(buf + pos, remaining(pos), "%d:",
544 desc->lineno);
545 if (pos - pos_after_tid)
546 pos += snprintf(buf + pos, remaining(pos), " ");
547 if (pos >= PREFIX_SIZE)
548 buf[PREFIX_SIZE - 1] = '\0';
549
550 return buf;
551}
552
553void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
554{
555 va_list args;
556 struct va_format vaf;
557 char buf[PREFIX_SIZE];
558
559 BUG_ON(!descriptor);
560 BUG_ON(!fmt);
561
562 va_start(args, fmt);
563
564 vaf.fmt = fmt;
565 vaf.va = &args;
566
567 printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
568
569 va_end(args);
570}
571EXPORT_SYMBOL(__dynamic_pr_debug);
572
573void __dynamic_dev_dbg(struct _ddebug *descriptor,
574 const struct device *dev, const char *fmt, ...)
575{
576 struct va_format vaf;
577 va_list args;
578
579 BUG_ON(!descriptor);
580 BUG_ON(!fmt);
581
582 va_start(args, fmt);
583
584 vaf.fmt = fmt;
585 vaf.va = &args;
586
587 if (!dev) {
588 printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
589 } else {
590 char buf[PREFIX_SIZE];
591
592 dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
593 dynamic_emit_prefix(descriptor, buf),
594 dev_driver_string(dev), dev_name(dev),
595 &vaf);
596 }
597
598 va_end(args);
599}
600EXPORT_SYMBOL(__dynamic_dev_dbg);
601
602#ifdef CONFIG_NET
603
604void __dynamic_netdev_dbg(struct _ddebug *descriptor,
605 const struct net_device *dev, const char *fmt, ...)
606{
607 struct va_format vaf;
608 va_list args;
609
610 BUG_ON(!descriptor);
611 BUG_ON(!fmt);
612
613 va_start(args, fmt);
614
615 vaf.fmt = fmt;
616 vaf.va = &args;
617
618 if (dev && dev->dev.parent) {
619 char buf[PREFIX_SIZE];
620
621 dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
622 "%s%s %s %s%s: %pV",
623 dynamic_emit_prefix(descriptor, buf),
624 dev_driver_string(dev->dev.parent),
625 dev_name(dev->dev.parent),
626 netdev_name(dev), netdev_reg_state(dev),
627 &vaf);
628 } else if (dev) {
629 printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
630 netdev_reg_state(dev), &vaf);
631 } else {
632 printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
633 }
634
635 va_end(args);
636}
637EXPORT_SYMBOL(__dynamic_netdev_dbg);
638
639#endif
640
641#if IS_ENABLED(CONFIG_INFINIBAND)
642
643void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
644 const struct ib_device *ibdev, const char *fmt, ...)
645{
646 struct va_format vaf;
647 va_list args;
648
649 va_start(args, fmt);
650
651 vaf.fmt = fmt;
652 vaf.va = &args;
653
654 if (ibdev && ibdev->dev.parent) {
655 char buf[PREFIX_SIZE];
656
657 dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
658 "%s%s %s %s: %pV",
659 dynamic_emit_prefix(descriptor, buf),
660 dev_driver_string(ibdev->dev.parent),
661 dev_name(ibdev->dev.parent),
662 dev_name(&ibdev->dev),
663 &vaf);
664 } else if (ibdev) {
665 printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
666 } else {
667 printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
668 }
669
670 va_end(args);
671}
672EXPORT_SYMBOL(__dynamic_ibdev_dbg);
673
674#endif
675
676#define DDEBUG_STRING_SIZE 1024
677static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
678
679static __init int ddebug_setup_query(char *str)
680{
681 if (strlen(str) >= DDEBUG_STRING_SIZE) {
682 pr_warn("ddebug boot param string too large\n");
683 return 0;
684 }
685 strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
686 return 1;
687}
688
689__setup("ddebug_query=", ddebug_setup_query);
690
691/*
692 * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
693 * command text from userspace, parses and executes it.
694 */
695#define USER_BUF_PAGE 4096
696static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
697 size_t len, loff_t *offp)
698{
699 char *tmpbuf;
700 int ret;
701
702 if (len == 0)
703 return 0;
704 if (len > USER_BUF_PAGE - 1) {
705 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
706 return -E2BIG;
707 }
708 tmpbuf = memdup_user_nul(ubuf, len);
709 if (IS_ERR(tmpbuf))
710 return PTR_ERR(tmpbuf);
711 vpr_info("read %d bytes from userspace\n", (int)len);
712
713 ret = ddebug_exec_queries(tmpbuf, NULL);
714 kfree(tmpbuf);
715 if (ret < 0)
716 return ret;
717
718 *offp += len;
719 return len;
720}
721
722/*
723 * Set the iterator to point to the first _ddebug object
724 * and return a pointer to that first object. Returns
725 * NULL if there are no _ddebugs at all.
726 */
727static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
728{
729 if (list_empty(&ddebug_tables)) {
730 iter->table = NULL;
731 iter->idx = 0;
732 return NULL;
733 }
734 iter->table = list_entry(ddebug_tables.next,
735 struct ddebug_table, link);
736 iter->idx = 0;
737 return &iter->table->ddebugs[iter->idx];
738}
739
740/*
741 * Advance the iterator to point to the next _ddebug
742 * object from the one the iterator currently points at,
743 * and returns a pointer to the new _ddebug. Returns
744 * NULL if the iterator has seen all the _ddebugs.
745 */
746static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
747{
748 if (iter->table == NULL)
749 return NULL;
750 if (++iter->idx == iter->table->num_ddebugs) {
751 /* iterate to next table */
752 iter->idx = 0;
753 if (list_is_last(&iter->table->link, &ddebug_tables)) {
754 iter->table = NULL;
755 return NULL;
756 }
757 iter->table = list_entry(iter->table->link.next,
758 struct ddebug_table, link);
759 }
760 return &iter->table->ddebugs[iter->idx];
761}
762
763/*
764 * Seq_ops start method. Called at the start of every
765 * read() call from userspace. Takes the ddebug_lock and
766 * seeks the seq_file's iterator to the given position.
767 */
768static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
769{
770 struct ddebug_iter *iter = m->private;
771 struct _ddebug *dp;
772 int n = *pos;
773
774 vpr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos);
775
776 mutex_lock(&ddebug_lock);
777
778 if (!n)
779 return SEQ_START_TOKEN;
780 if (n < 0)
781 return NULL;
782 dp = ddebug_iter_first(iter);
783 while (dp != NULL && --n > 0)
784 dp = ddebug_iter_next(iter);
785 return dp;
786}
787
788/*
789 * Seq_ops next method. Called several times within a read()
790 * call from userspace, with ddebug_lock held. Walks to the
791 * next _ddebug object with a special case for the header line.
792 */
793static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
794{
795 struct ddebug_iter *iter = m->private;
796 struct _ddebug *dp;
797
798 vpr_info("called m=%p p=%p *pos=%lld\n",
799 m, p, (unsigned long long)*pos);
800
801 if (p == SEQ_START_TOKEN)
802 dp = ddebug_iter_first(iter);
803 else
804 dp = ddebug_iter_next(iter);
805 ++*pos;
806 return dp;
807}
808
809/*
810 * Seq_ops show method. Called several times within a read()
811 * call from userspace, with ddebug_lock held. Formats the
812 * current _ddebug as a single human-readable line, with a
813 * special case for the header line.
814 */
815static int ddebug_proc_show(struct seq_file *m, void *p)
816{
817 struct ddebug_iter *iter = m->private;
818 struct _ddebug *dp = p;
819 char flagsbuf[10];
820
821 vpr_info("called m=%p p=%p\n", m, p);
822
823 if (p == SEQ_START_TOKEN) {
824 seq_puts(m,
825 "# filename:lineno [module]function flags format\n");
826 return 0;
827 }
828
829 seq_printf(m, "%s:%u [%s]%s =%s \"",
830 trim_prefix(dp->filename), dp->lineno,
831 iter->table->mod_name, dp->function,
832 ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
833 seq_escape(m, dp->format, "\t\r\n\"");
834 seq_puts(m, "\"\n");
835
836 return 0;
837}
838
839/*
840 * Seq_ops stop method. Called at the end of each read()
841 * call from userspace. Drops ddebug_lock.
842 */
843static void ddebug_proc_stop(struct seq_file *m, void *p)
844{
845 vpr_info("called m=%p p=%p\n", m, p);
846 mutex_unlock(&ddebug_lock);
847}
848
849static const struct seq_operations ddebug_proc_seqops = {
850 .start = ddebug_proc_start,
851 .next = ddebug_proc_next,
852 .show = ddebug_proc_show,
853 .stop = ddebug_proc_stop
854};
855
856/*
857 * File_ops->open method for <debugfs>/dynamic_debug/control. Does
858 * the seq_file setup dance, and also creates an iterator to walk the
859 * _ddebugs. Note that we create a seq_file always, even for O_WRONLY
860 * files where it's not needed, as doing so simplifies the ->release
861 * method.
862 */
863static int ddebug_proc_open(struct inode *inode, struct file *file)
864{
865 vpr_info("called\n");
866 return seq_open_private(file, &ddebug_proc_seqops,
867 sizeof(struct ddebug_iter));
868}
869
870static const struct file_operations ddebug_proc_fops = {
871 .owner = THIS_MODULE,
872 .open = ddebug_proc_open,
873 .read = seq_read,
874 .llseek = seq_lseek,
875 .release = seq_release_private,
876 .write = ddebug_proc_write
877};
878
879/*
880 * Allocate a new ddebug_table for the given module
881 * and add it to the global list.
882 */
883int ddebug_add_module(struct _ddebug *tab, unsigned int n,
884 const char *name)
885{
886 struct ddebug_table *dt;
887
888 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
889 if (dt == NULL) {
890 pr_err("error adding module: %s\n", name);
891 return -ENOMEM;
892 }
893 /*
894 * For built-in modules, name lives in .rodata and is
895 * immortal. For loaded modules, name points at the name[]
896 * member of struct module, which lives at least as long as
897 * this struct ddebug_table.
898 */
899 dt->mod_name = name;
900 dt->num_ddebugs = n;
901 dt->ddebugs = tab;
902
903 mutex_lock(&ddebug_lock);
904 list_add_tail(&dt->link, &ddebug_tables);
905 mutex_unlock(&ddebug_lock);
906
907 vpr_info("%u debug prints in module %s\n", n, dt->mod_name);
908 return 0;
909}
910
911/* helper for ddebug_dyndbg_(boot|module)_param_cb */
912static int ddebug_dyndbg_param_cb(char *param, char *val,
913 const char *modname, int on_err)
914{
915 char *sep;
916
917 sep = strchr(param, '.');
918 if (sep) {
919 /* needed only for ddebug_dyndbg_boot_param_cb */
920 *sep = '\0';
921 modname = param;
922 param = sep + 1;
923 }
924 if (strcmp(param, "dyndbg"))
925 return on_err; /* determined by caller */
926
927 ddebug_exec_queries((val ? val : "+p"), modname);
928
929 return 0; /* query failure shouldnt stop module load */
930}
931
932/* handle both dyndbg and $module.dyndbg params at boot */
933static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
934 const char *unused, void *arg)
935{
936 vpr_info("%s=\"%s\"\n", param, val);
937 return ddebug_dyndbg_param_cb(param, val, NULL, 0);
938}
939
940/*
941 * modprobe foo finds foo.params in boot-args, strips "foo.", and
942 * passes them to load_module(). This callback gets unknown params,
943 * processes dyndbg params, rejects others.
944 */
945int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
946{
947 vpr_info("module: %s %s=\"%s\"\n", module, param, val);
948 return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
949}
950
951static void ddebug_table_free(struct ddebug_table *dt)
952{
953 list_del_init(&dt->link);
954 kfree(dt);
955}
956
957/*
958 * Called in response to a module being unloaded. Removes
959 * any ddebug_table's which point at the module.
960 */
961int ddebug_remove_module(const char *mod_name)
962{
963 struct ddebug_table *dt, *nextdt;
964 int ret = -ENOENT;
965
966 vpr_info("removing module \"%s\"\n", mod_name);
967
968 mutex_lock(&ddebug_lock);
969 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
970 if (dt->mod_name == mod_name) {
971 ddebug_table_free(dt);
972 ret = 0;
973 break;
974 }
975 }
976 mutex_unlock(&ddebug_lock);
977 return ret;
978}
979
980static void ddebug_remove_all_tables(void)
981{
982 mutex_lock(&ddebug_lock);
983 while (!list_empty(&ddebug_tables)) {
984 struct ddebug_table *dt = list_entry(ddebug_tables.next,
985 struct ddebug_table,
986 link);
987 ddebug_table_free(dt);
988 }
989 mutex_unlock(&ddebug_lock);
990}
991
992static __initdata int ddebug_init_success;
993
994static int __init dynamic_debug_init_debugfs(void)
995{
996 struct dentry *dir;
997
998 if (!ddebug_init_success)
999 return -ENODEV;
1000
1001 dir = debugfs_create_dir("dynamic_debug", NULL);
1002 debugfs_create_file("control", 0644, dir, NULL, &ddebug_proc_fops);
1003
1004 return 0;
1005}
1006
1007static int __init dynamic_debug_init(void)
1008{
1009 struct _ddebug *iter, *iter_start;
1010 const char *modname = NULL;
1011 char *cmdline;
1012 int ret = 0;
1013 int n = 0, entries = 0, modct = 0;
1014 int verbose_bytes = 0;
1015
1016 if (__start___verbose == __stop___verbose) {
1017 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1018 return 1;
1019 }
1020 iter = __start___verbose;
1021 modname = iter->modname;
1022 iter_start = iter;
1023 for (; iter < __stop___verbose; iter++) {
1024 entries++;
1025 verbose_bytes += strlen(iter->modname) + strlen(iter->function)
1026 + strlen(iter->filename) + strlen(iter->format);
1027
1028 if (strcmp(modname, iter->modname)) {
1029 modct++;
1030 ret = ddebug_add_module(iter_start, n, modname);
1031 if (ret)
1032 goto out_err;
1033 n = 0;
1034 modname = iter->modname;
1035 iter_start = iter;
1036 }
1037 n++;
1038 }
1039 ret = ddebug_add_module(iter_start, n, modname);
1040 if (ret)
1041 goto out_err;
1042
1043 ddebug_init_success = 1;
1044 vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in (readonly) verbose section\n",
1045 modct, entries, (int)(modct * sizeof(struct ddebug_table)),
1046 verbose_bytes + (int)(__stop___verbose - __start___verbose));
1047
1048 /* apply ddebug_query boot param, dont unload tables on err */
1049 if (ddebug_setup_string[0] != '\0') {
1050 pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n");
1051 ret = ddebug_exec_queries(ddebug_setup_string, NULL);
1052 if (ret < 0)
1053 pr_warn("Invalid ddebug boot param %s\n",
1054 ddebug_setup_string);
1055 else
1056 pr_info("%d changes by ddebug_query\n", ret);
1057 }
1058 /* now that ddebug tables are loaded, process all boot args
1059 * again to find and activate queries given in dyndbg params.
1060 * While this has already been done for known boot params, it
1061 * ignored the unknown ones (dyndbg in particular). Reusing
1062 * parse_args avoids ad-hoc parsing. This will also attempt
1063 * to activate queries for not-yet-loaded modules, which is
1064 * slightly noisy if verbose, but harmless.
1065 */
1066 cmdline = kstrdup(saved_command_line, GFP_KERNEL);
1067 parse_args("dyndbg params", cmdline, NULL,
1068 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
1069 kfree(cmdline);
1070 return 0;
1071
1072out_err:
1073 ddebug_remove_all_tables();
1074 return 0;
1075}
1076/* Allow early initialization for boot messages via boot param */
1077early_initcall(dynamic_debug_init);
1078
1079/* Debugfs setup must be done later */
1080fs_initcall(dynamic_debug_init_debugfs);