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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 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 dp->flags = newflags;
192 vpr_info("changed %s:%d [%s]%s =%s\n",
193 trim_prefix(dp->filename), dp->lineno,
194 dt->mod_name, dp->function,
195 ddebug_describe_flags(dp, flagbuf,
196 sizeof(flagbuf)));
197 }
198 }
199 mutex_unlock(&ddebug_lock);
200
201 if (!nfound && verbose)
202 pr_info("no matches for query\n");
203
204 return nfound;
205}
206
207/*
208 * Split the buffer `buf' into space-separated words.
209 * Handles simple " and ' quoting, i.e. without nested,
210 * embedded or escaped \". Return the number of words
211 * or <0 on error.
212 */
213static int ddebug_tokenize(char *buf, char *words[], int maxwords)
214{
215 int nwords = 0;
216
217 while (*buf) {
218 char *end;
219
220 /* Skip leading whitespace */
221 buf = skip_spaces(buf);
222 if (!*buf)
223 break; /* oh, it was trailing whitespace */
224 if (*buf == '#')
225 break; /* token starts comment, skip rest of line */
226
227 /* find `end' of word, whitespace separated or quoted */
228 if (*buf == '"' || *buf == '\'') {
229 int quote = *buf++;
230 for (end = buf; *end && *end != quote; end++)
231 ;
232 if (!*end) {
233 pr_err("unclosed quote: %s\n", buf);
234 return -EINVAL; /* unclosed quote */
235 }
236 } else {
237 for (end = buf; *end && !isspace(*end); end++)
238 ;
239 BUG_ON(end == buf);
240 }
241
242 /* `buf' is start of word, `end' is one past its end */
243 if (nwords == maxwords) {
244 pr_err("too many words, legal max <=%d\n", maxwords);
245 return -EINVAL; /* ran out of words[] before bytes */
246 }
247 if (*end)
248 *end++ = '\0'; /* terminate the word */
249 words[nwords++] = buf;
250 buf = end;
251 }
252
253 if (verbose) {
254 int i;
255 pr_info("split into words:");
256 for (i = 0; i < nwords; i++)
257 pr_cont(" \"%s\"", words[i]);
258 pr_cont("\n");
259 }
260
261 return nwords;
262}
263
264/*
265 * Parse a single line number. Note that the empty string ""
266 * is treated as a special case and converted to zero, which
267 * is later treated as a "don't care" value.
268 */
269static inline int parse_lineno(const char *str, unsigned int *val)
270{
271 BUG_ON(str == NULL);
272 if (*str == '\0') {
273 *val = 0;
274 return 0;
275 }
276 if (kstrtouint(str, 10, val) < 0) {
277 pr_err("bad line-number: %s\n", str);
278 return -EINVAL;
279 }
280 return 0;
281}
282
283static int check_set(const char **dest, char *src, char *name)
284{
285 int rc = 0;
286
287 if (*dest) {
288 rc = -EINVAL;
289 pr_err("match-spec:%s val:%s overridden by %s\n",
290 name, *dest, src);
291 }
292 *dest = src;
293 return rc;
294}
295
296/*
297 * Parse words[] as a ddebug query specification, which is a series
298 * of (keyword, value) pairs chosen from these possibilities:
299 *
300 * func <function-name>
301 * file <full-pathname>
302 * file <base-filename>
303 * module <module-name>
304 * format <escaped-string-to-find-in-format>
305 * line <lineno>
306 * line <first-lineno>-<last-lineno> // where either may be empty
307 *
308 * Only 1 of each type is allowed.
309 * Returns 0 on success, <0 on error.
310 */
311static int ddebug_parse_query(char *words[], int nwords,
312 struct ddebug_query *query, const char *modname)
313{
314 unsigned int i;
315 int rc = 0;
316
317 /* check we have an even number of words */
318 if (nwords % 2 != 0) {
319 pr_err("expecting pairs of match-spec <value>\n");
320 return -EINVAL;
321 }
322 memset(query, 0, sizeof(*query));
323
324 if (modname)
325 /* support $modname.dyndbg=<multiple queries> */
326 query->module = modname;
327
328 for (i = 0; i < nwords; i += 2) {
329 if (!strcmp(words[i], "func")) {
330 rc = check_set(&query->function, words[i+1], "func");
331 } else if (!strcmp(words[i], "file")) {
332 rc = check_set(&query->filename, words[i+1], "file");
333 } else if (!strcmp(words[i], "module")) {
334 rc = check_set(&query->module, words[i+1], "module");
335 } else if (!strcmp(words[i], "format")) {
336 string_unescape_inplace(words[i+1], UNESCAPE_SPACE |
337 UNESCAPE_OCTAL |
338 UNESCAPE_SPECIAL);
339 rc = check_set(&query->format, words[i+1], "format");
340 } else if (!strcmp(words[i], "line")) {
341 char *first = words[i+1];
342 char *last = strchr(first, '-');
343 if (query->first_lineno || query->last_lineno) {
344 pr_err("match-spec: line used 2x\n");
345 return -EINVAL;
346 }
347 if (last)
348 *last++ = '\0';
349 if (parse_lineno(first, &query->first_lineno) < 0)
350 return -EINVAL;
351 if (last) {
352 /* range <first>-<last> */
353 if (parse_lineno(last, &query->last_lineno) < 0)
354 return -EINVAL;
355
356 if (query->last_lineno < query->first_lineno) {
357 pr_err("last-line:%d < 1st-line:%d\n",
358 query->last_lineno,
359 query->first_lineno);
360 return -EINVAL;
361 }
362 } else {
363 query->last_lineno = query->first_lineno;
364 }
365 } else {
366 pr_err("unknown keyword \"%s\"\n", words[i]);
367 return -EINVAL;
368 }
369 if (rc)
370 return rc;
371 }
372 vpr_info_dq(query, "parsed");
373 return 0;
374}
375
376/*
377 * Parse `str' as a flags specification, format [-+=][p]+.
378 * Sets up *maskp and *flagsp to be used when changing the
379 * flags fields of matched _ddebug's. Returns 0 on success
380 * or <0 on error.
381 */
382static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
383 unsigned int *maskp)
384{
385 unsigned flags = 0;
386 int op = '=', i;
387
388 switch (*str) {
389 case '+':
390 case '-':
391 case '=':
392 op = *str++;
393 break;
394 default:
395 pr_err("bad flag-op %c, at start of %s\n", *str, str);
396 return -EINVAL;
397 }
398 vpr_info("op='%c'\n", op);
399
400 for (; *str ; ++str) {
401 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
402 if (*str == opt_array[i].opt_char) {
403 flags |= opt_array[i].flag;
404 break;
405 }
406 }
407 if (i < 0) {
408 pr_err("unknown flag '%c' in \"%s\"\n", *str, str);
409 return -EINVAL;
410 }
411 }
412 vpr_info("flags=0x%x\n", flags);
413
414 /* calculate final *flagsp, *maskp according to mask and op */
415 switch (op) {
416 case '=':
417 *maskp = 0;
418 *flagsp = flags;
419 break;
420 case '+':
421 *maskp = ~0U;
422 *flagsp = flags;
423 break;
424 case '-':
425 *maskp = ~flags;
426 *flagsp = 0;
427 break;
428 }
429 vpr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp);
430 return 0;
431}
432
433static int ddebug_exec_query(char *query_string, const char *modname)
434{
435 unsigned int flags = 0, mask = 0;
436 struct ddebug_query query;
437#define MAXWORDS 9
438 int nwords, nfound;
439 char *words[MAXWORDS];
440
441 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
442 if (nwords <= 0) {
443 pr_err("tokenize failed\n");
444 return -EINVAL;
445 }
446 /* check flags 1st (last arg) so query is pairs of spec,val */
447 if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) {
448 pr_err("flags parse failed\n");
449 return -EINVAL;
450 }
451 if (ddebug_parse_query(words, nwords-1, &query, modname)) {
452 pr_err("query parse failed\n");
453 return -EINVAL;
454 }
455 /* actually go and implement the change */
456 nfound = ddebug_change(&query, flags, mask);
457 vpr_info_dq(&query, nfound ? "applied" : "no-match");
458
459 return nfound;
460}
461
462/* handle multiple queries in query string, continue on error, return
463 last error or number of matching callsites. Module name is either
464 in param (for boot arg) or perhaps in query string.
465*/
466static int ddebug_exec_queries(char *query, const char *modname)
467{
468 char *split;
469 int i, errs = 0, exitcode = 0, rc, nfound = 0;
470
471 for (i = 0; query; query = split) {
472 split = strpbrk(query, ";\n");
473 if (split)
474 *split++ = '\0';
475
476 query = skip_spaces(query);
477 if (!query || !*query || *query == '#')
478 continue;
479
480 vpr_info("query %d: \"%s\"\n", i, query);
481
482 rc = ddebug_exec_query(query, modname);
483 if (rc < 0) {
484 errs++;
485 exitcode = rc;
486 } else {
487 nfound += rc;
488 }
489 i++;
490 }
491 vpr_info("processed %d queries, with %d matches, %d errs\n",
492 i, nfound, errs);
493
494 if (exitcode)
495 return exitcode;
496 return nfound;
497}
498
499#define PREFIX_SIZE 64
500
501static int remaining(int wrote)
502{
503 if (PREFIX_SIZE - wrote > 0)
504 return PREFIX_SIZE - wrote;
505 return 0;
506}
507
508static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
509{
510 int pos_after_tid;
511 int pos = 0;
512
513 *buf = '\0';
514
515 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
516 if (in_interrupt())
517 pos += snprintf(buf + pos, remaining(pos), "<intr> ");
518 else
519 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
520 task_pid_vnr(current));
521 }
522 pos_after_tid = pos;
523 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
524 pos += snprintf(buf + pos, remaining(pos), "%s:",
525 desc->modname);
526 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
527 pos += snprintf(buf + pos, remaining(pos), "%s:",
528 desc->function);
529 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
530 pos += snprintf(buf + pos, remaining(pos), "%d:",
531 desc->lineno);
532 if (pos - pos_after_tid)
533 pos += snprintf(buf + pos, remaining(pos), " ");
534 if (pos >= PREFIX_SIZE)
535 buf[PREFIX_SIZE - 1] = '\0';
536
537 return buf;
538}
539
540int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
541{
542 va_list args;
543 int res;
544 struct va_format vaf;
545 char buf[PREFIX_SIZE];
546
547 BUG_ON(!descriptor);
548 BUG_ON(!fmt);
549
550 va_start(args, fmt);
551
552 vaf.fmt = fmt;
553 vaf.va = &args;
554
555 res = printk(KERN_DEBUG "%s%pV",
556 dynamic_emit_prefix(descriptor, buf), &vaf);
557
558 va_end(args);
559
560 return res;
561}
562EXPORT_SYMBOL(__dynamic_pr_debug);
563
564int __dynamic_dev_dbg(struct _ddebug *descriptor,
565 const struct device *dev, const char *fmt, ...)
566{
567 struct va_format vaf;
568 va_list args;
569 int res;
570
571 BUG_ON(!descriptor);
572 BUG_ON(!fmt);
573
574 va_start(args, fmt);
575
576 vaf.fmt = fmt;
577 vaf.va = &args;
578
579 if (!dev) {
580 res = printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
581 } else {
582 char buf[PREFIX_SIZE];
583
584 res = dev_printk_emit(7, dev, "%s%s %s: %pV",
585 dynamic_emit_prefix(descriptor, buf),
586 dev_driver_string(dev), dev_name(dev),
587 &vaf);
588 }
589
590 va_end(args);
591
592 return res;
593}
594EXPORT_SYMBOL(__dynamic_dev_dbg);
595
596#ifdef CONFIG_NET
597
598int __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 int res;
604
605 BUG_ON(!descriptor);
606 BUG_ON(!fmt);
607
608 va_start(args, fmt);
609
610 vaf.fmt = fmt;
611 vaf.va = &args;
612
613 if (dev && dev->dev.parent) {
614 char buf[PREFIX_SIZE];
615
616 res = dev_printk_emit(7, dev->dev.parent,
617 "%s%s %s %s: %pV",
618 dynamic_emit_prefix(descriptor, buf),
619 dev_driver_string(dev->dev.parent),
620 dev_name(dev->dev.parent),
621 netdev_name(dev), &vaf);
622 } else if (dev) {
623 res = printk(KERN_DEBUG "%s: %pV", netdev_name(dev), &vaf);
624 } else {
625 res = printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
626 }
627
628 va_end(args);
629
630 return res;
631}
632EXPORT_SYMBOL(__dynamic_netdev_dbg);
633
634#endif
635
636#define DDEBUG_STRING_SIZE 1024
637static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
638
639static __init int ddebug_setup_query(char *str)
640{
641 if (strlen(str) >= DDEBUG_STRING_SIZE) {
642 pr_warn("ddebug boot param string too large\n");
643 return 0;
644 }
645 strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
646 return 1;
647}
648
649__setup("ddebug_query=", ddebug_setup_query);
650
651/*
652 * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the
653 * command text from userspace, parses and executes it.
654 */
655#define USER_BUF_PAGE 4096
656static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
657 size_t len, loff_t *offp)
658{
659 char *tmpbuf;
660 int ret;
661
662 if (len == 0)
663 return 0;
664 if (len > USER_BUF_PAGE - 1) {
665 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
666 return -E2BIG;
667 }
668 tmpbuf = kmalloc(len + 1, GFP_KERNEL);
669 if (!tmpbuf)
670 return -ENOMEM;
671 if (copy_from_user(tmpbuf, ubuf, len)) {
672 kfree(tmpbuf);
673 return -EFAULT;
674 }
675 tmpbuf[len] = '\0';
676 vpr_info("read %d bytes from userspace\n", (int)len);
677
678 ret = ddebug_exec_queries(tmpbuf, NULL);
679 kfree(tmpbuf);
680 if (ret < 0)
681 return ret;
682
683 *offp += len;
684 return len;
685}
686
687/*
688 * Set the iterator to point to the first _ddebug object
689 * and return a pointer to that first object. Returns
690 * NULL if there are no _ddebugs at all.
691 */
692static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
693{
694 if (list_empty(&ddebug_tables)) {
695 iter->table = NULL;
696 iter->idx = 0;
697 return NULL;
698 }
699 iter->table = list_entry(ddebug_tables.next,
700 struct ddebug_table, link);
701 iter->idx = 0;
702 return &iter->table->ddebugs[iter->idx];
703}
704
705/*
706 * Advance the iterator to point to the next _ddebug
707 * object from the one the iterator currently points at,
708 * and returns a pointer to the new _ddebug. Returns
709 * NULL if the iterator has seen all the _ddebugs.
710 */
711static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
712{
713 if (iter->table == NULL)
714 return NULL;
715 if (++iter->idx == iter->table->num_ddebugs) {
716 /* iterate to next table */
717 iter->idx = 0;
718 if (list_is_last(&iter->table->link, &ddebug_tables)) {
719 iter->table = NULL;
720 return NULL;
721 }
722 iter->table = list_entry(iter->table->link.next,
723 struct ddebug_table, link);
724 }
725 return &iter->table->ddebugs[iter->idx];
726}
727
728/*
729 * Seq_ops start method. Called at the start of every
730 * read() call from userspace. Takes the ddebug_lock and
731 * seeks the seq_file's iterator to the given position.
732 */
733static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
734{
735 struct ddebug_iter *iter = m->private;
736 struct _ddebug *dp;
737 int n = *pos;
738
739 vpr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos);
740
741 mutex_lock(&ddebug_lock);
742
743 if (!n)
744 return SEQ_START_TOKEN;
745 if (n < 0)
746 return NULL;
747 dp = ddebug_iter_first(iter);
748 while (dp != NULL && --n > 0)
749 dp = ddebug_iter_next(iter);
750 return dp;
751}
752
753/*
754 * Seq_ops next method. Called several times within a read()
755 * call from userspace, with ddebug_lock held. Walks to the
756 * next _ddebug object with a special case for the header line.
757 */
758static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
759{
760 struct ddebug_iter *iter = m->private;
761 struct _ddebug *dp;
762
763 vpr_info("called m=%p p=%p *pos=%lld\n",
764 m, p, (unsigned long long)*pos);
765
766 if (p == SEQ_START_TOKEN)
767 dp = ddebug_iter_first(iter);
768 else
769 dp = ddebug_iter_next(iter);
770 ++*pos;
771 return dp;
772}
773
774/*
775 * Seq_ops show method. Called several times within a read()
776 * call from userspace, with ddebug_lock held. Formats the
777 * current _ddebug as a single human-readable line, with a
778 * special case for the header line.
779 */
780static int ddebug_proc_show(struct seq_file *m, void *p)
781{
782 struct ddebug_iter *iter = m->private;
783 struct _ddebug *dp = p;
784 char flagsbuf[10];
785
786 vpr_info("called m=%p p=%p\n", m, p);
787
788 if (p == SEQ_START_TOKEN) {
789 seq_puts(m,
790 "# filename:lineno [module]function flags format\n");
791 return 0;
792 }
793
794 seq_printf(m, "%s:%u [%s]%s =%s \"",
795 trim_prefix(dp->filename), dp->lineno,
796 iter->table->mod_name, dp->function,
797 ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
798 seq_escape(m, dp->format, "\t\r\n\"");
799 seq_puts(m, "\"\n");
800
801 return 0;
802}
803
804/*
805 * Seq_ops stop method. Called at the end of each read()
806 * call from userspace. Drops ddebug_lock.
807 */
808static void ddebug_proc_stop(struct seq_file *m, void *p)
809{
810 vpr_info("called m=%p p=%p\n", m, p);
811 mutex_unlock(&ddebug_lock);
812}
813
814static const struct seq_operations ddebug_proc_seqops = {
815 .start = ddebug_proc_start,
816 .next = ddebug_proc_next,
817 .show = ddebug_proc_show,
818 .stop = ddebug_proc_stop
819};
820
821/*
822 * File_ops->open method for <debugfs>/dynamic_debug/control. Does
823 * the seq_file setup dance, and also creates an iterator to walk the
824 * _ddebugs. Note that we create a seq_file always, even for O_WRONLY
825 * files where it's not needed, as doing so simplifies the ->release
826 * method.
827 */
828static int ddebug_proc_open(struct inode *inode, struct file *file)
829{
830 struct ddebug_iter *iter;
831 int err;
832
833 vpr_info("called\n");
834
835 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
836 if (iter == NULL)
837 return -ENOMEM;
838
839 err = seq_open(file, &ddebug_proc_seqops);
840 if (err) {
841 kfree(iter);
842 return err;
843 }
844 ((struct seq_file *)file->private_data)->private = iter;
845 return 0;
846}
847
848static const struct file_operations ddebug_proc_fops = {
849 .owner = THIS_MODULE,
850 .open = ddebug_proc_open,
851 .read = seq_read,
852 .llseek = seq_lseek,
853 .release = seq_release_private,
854 .write = ddebug_proc_write
855};
856
857/*
858 * Allocate a new ddebug_table for the given module
859 * and add it to the global list.
860 */
861int ddebug_add_module(struct _ddebug *tab, unsigned int n,
862 const char *name)
863{
864 struct ddebug_table *dt;
865 char *new_name;
866
867 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
868 if (dt == NULL)
869 return -ENOMEM;
870 new_name = kstrdup(name, GFP_KERNEL);
871 if (new_name == NULL) {
872 kfree(dt);
873 return -ENOMEM;
874 }
875 dt->mod_name = new_name;
876 dt->num_ddebugs = n;
877 dt->ddebugs = tab;
878
879 mutex_lock(&ddebug_lock);
880 list_add_tail(&dt->link, &ddebug_tables);
881 mutex_unlock(&ddebug_lock);
882
883 vpr_info("%u debug prints in module %s\n", n, dt->mod_name);
884 return 0;
885}
886EXPORT_SYMBOL_GPL(ddebug_add_module);
887
888/* helper for ddebug_dyndbg_(boot|module)_param_cb */
889static int ddebug_dyndbg_param_cb(char *param, char *val,
890 const char *modname, int on_err)
891{
892 char *sep;
893
894 sep = strchr(param, '.');
895 if (sep) {
896 /* needed only for ddebug_dyndbg_boot_param_cb */
897 *sep = '\0';
898 modname = param;
899 param = sep + 1;
900 }
901 if (strcmp(param, "dyndbg"))
902 return on_err; /* determined by caller */
903
904 ddebug_exec_queries((val ? val : "+p"), modname);
905
906 return 0; /* query failure shouldnt stop module load */
907}
908
909/* handle both dyndbg and $module.dyndbg params at boot */
910static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
911 const char *unused)
912{
913 vpr_info("%s=\"%s\"\n", param, val);
914 return ddebug_dyndbg_param_cb(param, val, NULL, 0);
915}
916
917/*
918 * modprobe foo finds foo.params in boot-args, strips "foo.", and
919 * passes them to load_module(). This callback gets unknown params,
920 * processes dyndbg params, rejects others.
921 */
922int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
923{
924 vpr_info("module: %s %s=\"%s\"\n", module, param, val);
925 return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
926}
927
928static void ddebug_table_free(struct ddebug_table *dt)
929{
930 list_del_init(&dt->link);
931 kfree(dt->mod_name);
932 kfree(dt);
933}
934
935/*
936 * Called in response to a module being unloaded. Removes
937 * any ddebug_table's which point at the module.
938 */
939int ddebug_remove_module(const char *mod_name)
940{
941 struct ddebug_table *dt, *nextdt;
942 int ret = -ENOENT;
943
944 vpr_info("removing module \"%s\"\n", mod_name);
945
946 mutex_lock(&ddebug_lock);
947 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
948 if (!strcmp(dt->mod_name, mod_name)) {
949 ddebug_table_free(dt);
950 ret = 0;
951 }
952 }
953 mutex_unlock(&ddebug_lock);
954 return ret;
955}
956EXPORT_SYMBOL_GPL(ddebug_remove_module);
957
958static void ddebug_remove_all_tables(void)
959{
960 mutex_lock(&ddebug_lock);
961 while (!list_empty(&ddebug_tables)) {
962 struct ddebug_table *dt = list_entry(ddebug_tables.next,
963 struct ddebug_table,
964 link);
965 ddebug_table_free(dt);
966 }
967 mutex_unlock(&ddebug_lock);
968}
969
970static __initdata int ddebug_init_success;
971
972static int __init dynamic_debug_init_debugfs(void)
973{
974 struct dentry *dir, *file;
975
976 if (!ddebug_init_success)
977 return -ENODEV;
978
979 dir = debugfs_create_dir("dynamic_debug", NULL);
980 if (!dir)
981 return -ENOMEM;
982 file = debugfs_create_file("control", 0644, dir, NULL,
983 &ddebug_proc_fops);
984 if (!file) {
985 debugfs_remove(dir);
986 return -ENOMEM;
987 }
988 return 0;
989}
990
991static int __init dynamic_debug_init(void)
992{
993 struct _ddebug *iter, *iter_start;
994 const char *modname = NULL;
995 char *cmdline;
996 int ret = 0;
997 int n = 0, entries = 0, modct = 0;
998 int verbose_bytes = 0;
999
1000 if (__start___verbose == __stop___verbose) {
1001 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1002 return 1;
1003 }
1004 iter = __start___verbose;
1005 modname = iter->modname;
1006 iter_start = iter;
1007 for (; iter < __stop___verbose; iter++) {
1008 entries++;
1009 verbose_bytes += strlen(iter->modname) + strlen(iter->function)
1010 + strlen(iter->filename) + strlen(iter->format);
1011
1012 if (strcmp(modname, iter->modname)) {
1013 modct++;
1014 ret = ddebug_add_module(iter_start, n, modname);
1015 if (ret)
1016 goto out_err;
1017 n = 0;
1018 modname = iter->modname;
1019 iter_start = iter;
1020 }
1021 n++;
1022 }
1023 ret = ddebug_add_module(iter_start, n, modname);
1024 if (ret)
1025 goto out_err;
1026
1027 ddebug_init_success = 1;
1028 vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in (readonly) verbose section\n",
1029 modct, entries, (int)(modct * sizeof(struct ddebug_table)),
1030 verbose_bytes + (int)(__stop___verbose - __start___verbose));
1031
1032 /* apply ddebug_query boot param, dont unload tables on err */
1033 if (ddebug_setup_string[0] != '\0') {
1034 pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n");
1035 ret = ddebug_exec_queries(ddebug_setup_string, NULL);
1036 if (ret < 0)
1037 pr_warn("Invalid ddebug boot param %s\n",
1038 ddebug_setup_string);
1039 else
1040 pr_info("%d changes by ddebug_query\n", ret);
1041 }
1042 /* now that ddebug tables are loaded, process all boot args
1043 * again to find and activate queries given in dyndbg params.
1044 * While this has already been done for known boot params, it
1045 * ignored the unknown ones (dyndbg in particular). Reusing
1046 * parse_args avoids ad-hoc parsing. This will also attempt
1047 * to activate queries for not-yet-loaded modules, which is
1048 * slightly noisy if verbose, but harmless.
1049 */
1050 cmdline = kstrdup(saved_command_line, GFP_KERNEL);
1051 parse_args("dyndbg params", cmdline, NULL,
1052 0, 0, 0, &ddebug_dyndbg_boot_param_cb);
1053 kfree(cmdline);
1054 return 0;
1055
1056out_err:
1057 ddebug_remove_all_tables();
1058 return 0;
1059}
1060/* Allow early initialization for boot messages via boot param */
1061early_initcall(dynamic_debug_init);
1062
1063/* Debugfs setup must be done later */
1064fs_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);