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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) "dyndbg: " fmt
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___dyndbg[];
43extern struct _ddebug __stop___dyndbg[];
44extern struct ddebug_class_map __start___dyndbg_classes[];
45extern struct ddebug_class_map __stop___dyndbg_classes[];
46
47struct ddebug_table {
48 struct list_head link, maps;
49 const char *mod_name;
50 unsigned int num_ddebugs;
51 struct _ddebug *ddebugs;
52};
53
54struct ddebug_query {
55 const char *filename;
56 const char *module;
57 const char *function;
58 const char *format;
59 const char *class_string;
60 unsigned int first_lineno, last_lineno;
61};
62
63struct ddebug_iter {
64 struct ddebug_table *table;
65 int idx;
66};
67
68struct flag_settings {
69 unsigned int flags;
70 unsigned int mask;
71};
72
73static DEFINE_MUTEX(ddebug_lock);
74static LIST_HEAD(ddebug_tables);
75static int verbose;
76module_param(verbose, int, 0644);
77MODULE_PARM_DESC(verbose, " dynamic_debug/control processing "
78 "( 0 = off (default), 1 = module add/rm, 2 = >control summary, 3 = parsing, 4 = per-site changes)");
79
80/* Return the path relative to source root */
81static inline const char *trim_prefix(const char *path)
82{
83 int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
84
85 if (strncmp(path, __FILE__, skip))
86 skip = 0; /* prefix mismatch, don't skip */
87
88 return path + skip;
89}
90
91static const struct { unsigned flag:8; char opt_char; } opt_array[] = {
92 { _DPRINTK_FLAGS_PRINT, 'p' },
93 { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
94 { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
95 { _DPRINTK_FLAGS_INCL_SOURCENAME, 's' },
96 { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
97 { _DPRINTK_FLAGS_INCL_TID, 't' },
98 { _DPRINTK_FLAGS_NONE, '_' },
99};
100
101struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; };
102
103/* format a string into buf[] which describes the _ddebug's flags */
104static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb)
105{
106 char *p = fb->buf;
107 int i;
108
109 for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
110 if (flags & opt_array[i].flag)
111 *p++ = opt_array[i].opt_char;
112 if (p == fb->buf)
113 *p++ = '_';
114 *p = '\0';
115
116 return fb->buf;
117}
118
119#define vnpr_info(lvl, fmt, ...) \
120do { \
121 if (verbose >= lvl) \
122 pr_info(fmt, ##__VA_ARGS__); \
123} while (0)
124
125#define vpr_info(fmt, ...) vnpr_info(1, fmt, ##__VA_ARGS__)
126#define v2pr_info(fmt, ...) vnpr_info(2, fmt, ##__VA_ARGS__)
127#define v3pr_info(fmt, ...) vnpr_info(3, fmt, ##__VA_ARGS__)
128#define v4pr_info(fmt, ...) vnpr_info(4, fmt, ##__VA_ARGS__)
129
130static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
131{
132 /* trim any trailing newlines */
133 int fmtlen = 0;
134
135 if (query->format) {
136 fmtlen = strlen(query->format);
137 while (fmtlen && query->format[fmtlen - 1] == '\n')
138 fmtlen--;
139 }
140
141 v3pr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u class=%s\n",
142 msg,
143 query->function ?: "",
144 query->filename ?: "",
145 query->module ?: "",
146 fmtlen, query->format ?: "",
147 query->first_lineno, query->last_lineno, query->class_string);
148}
149
150static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
151 const char *class_string, int *class_id)
152{
153 struct ddebug_class_map *map;
154 int idx;
155
156 list_for_each_entry(map, &dt->maps, link) {
157 idx = match_string(map->class_names, map->length, class_string);
158 if (idx >= 0) {
159 *class_id = idx + map->base;
160 return map;
161 }
162 }
163 *class_id = -ENOENT;
164 return NULL;
165}
166
167#define __outvar /* filled by callee */
168/*
169 * Search the tables for _ddebug's which match the given `query' and
170 * apply the `flags' and `mask' to them. Returns number of matching
171 * callsites, normally the same as number of changes. If verbose,
172 * logs the changes. Takes ddebug_lock.
173 */
174static int ddebug_change(const struct ddebug_query *query,
175 struct flag_settings *modifiers)
176{
177 int i;
178 struct ddebug_table *dt;
179 unsigned int newflags;
180 unsigned int nfound = 0;
181 struct flagsbuf fbuf, nbuf;
182 struct ddebug_class_map *map = NULL;
183 int __outvar valid_class;
184
185 /* search for matching ddebugs */
186 mutex_lock(&ddebug_lock);
187 list_for_each_entry(dt, &ddebug_tables, link) {
188
189 /* match against the module name */
190 if (query->module &&
191 !match_wildcard(query->module, dt->mod_name))
192 continue;
193
194 if (query->class_string) {
195 map = ddebug_find_valid_class(dt, query->class_string, &valid_class);
196 if (!map)
197 continue;
198 } else {
199 /* constrain query, do not touch class'd callsites */
200 valid_class = _DPRINTK_CLASS_DFLT;
201 }
202
203 for (i = 0; i < dt->num_ddebugs; i++) {
204 struct _ddebug *dp = &dt->ddebugs[i];
205
206 /* match site against query-class */
207 if (dp->class_id != valid_class)
208 continue;
209
210 /* match against the source filename */
211 if (query->filename &&
212 !match_wildcard(query->filename, dp->filename) &&
213 !match_wildcard(query->filename,
214 kbasename(dp->filename)) &&
215 !match_wildcard(query->filename,
216 trim_prefix(dp->filename)))
217 continue;
218
219 /* match against the function */
220 if (query->function &&
221 !match_wildcard(query->function, dp->function))
222 continue;
223
224 /* match against the format */
225 if (query->format) {
226 if (*query->format == '^') {
227 char *p;
228 /* anchored search. match must be at beginning */
229 p = strstr(dp->format, query->format+1);
230 if (p != dp->format)
231 continue;
232 } else if (!strstr(dp->format, query->format))
233 continue;
234 }
235
236 /* match against the line number range */
237 if (query->first_lineno &&
238 dp->lineno < query->first_lineno)
239 continue;
240 if (query->last_lineno &&
241 dp->lineno > query->last_lineno)
242 continue;
243
244 nfound++;
245
246 newflags = (dp->flags & modifiers->mask) | modifiers->flags;
247 if (newflags == dp->flags)
248 continue;
249#ifdef CONFIG_JUMP_LABEL
250 if (dp->flags & _DPRINTK_FLAGS_PRINT) {
251 if (!(newflags & _DPRINTK_FLAGS_PRINT))
252 static_branch_disable(&dp->key.dd_key_true);
253 } else if (newflags & _DPRINTK_FLAGS_PRINT) {
254 static_branch_enable(&dp->key.dd_key_true);
255 }
256#endif
257 v4pr_info("changed %s:%d [%s]%s %s => %s\n",
258 trim_prefix(dp->filename), dp->lineno,
259 dt->mod_name, dp->function,
260 ddebug_describe_flags(dp->flags, &fbuf),
261 ddebug_describe_flags(newflags, &nbuf));
262 dp->flags = newflags;
263 }
264 }
265 mutex_unlock(&ddebug_lock);
266
267 if (!nfound && verbose)
268 pr_info("no matches for query\n");
269
270 return nfound;
271}
272
273/*
274 * Split the buffer `buf' into space-separated words.
275 * Handles simple " and ' quoting, i.e. without nested,
276 * embedded or escaped \". Return the number of words
277 * or <0 on error.
278 */
279static int ddebug_tokenize(char *buf, char *words[], int maxwords)
280{
281 int nwords = 0;
282
283 while (*buf) {
284 char *end;
285
286 /* Skip leading whitespace */
287 buf = skip_spaces(buf);
288 if (!*buf)
289 break; /* oh, it was trailing whitespace */
290 if (*buf == '#')
291 break; /* token starts comment, skip rest of line */
292
293 /* find `end' of word, whitespace separated or quoted */
294 if (*buf == '"' || *buf == '\'') {
295 int quote = *buf++;
296 for (end = buf; *end && *end != quote; end++)
297 ;
298 if (!*end) {
299 pr_err("unclosed quote: %s\n", buf);
300 return -EINVAL; /* unclosed quote */
301 }
302 } else {
303 for (end = buf; *end && !isspace(*end); end++)
304 ;
305 BUG_ON(end == buf);
306 }
307
308 /* `buf' is start of word, `end' is one past its end */
309 if (nwords == maxwords) {
310 pr_err("too many words, legal max <=%d\n", maxwords);
311 return -EINVAL; /* ran out of words[] before bytes */
312 }
313 if (*end)
314 *end++ = '\0'; /* terminate the word */
315 words[nwords++] = buf;
316 buf = end;
317 }
318
319 if (verbose >= 3) {
320 int i;
321 pr_info("split into words:");
322 for (i = 0; i < nwords; i++)
323 pr_cont(" \"%s\"", words[i]);
324 pr_cont("\n");
325 }
326
327 return nwords;
328}
329
330/*
331 * Parse a single line number. Note that the empty string ""
332 * is treated as a special case and converted to zero, which
333 * is later treated as a "don't care" value.
334 */
335static inline int parse_lineno(const char *str, unsigned int *val)
336{
337 BUG_ON(str == NULL);
338 if (*str == '\0') {
339 *val = 0;
340 return 0;
341 }
342 if (kstrtouint(str, 10, val) < 0) {
343 pr_err("bad line-number: %s\n", str);
344 return -EINVAL;
345 }
346 return 0;
347}
348
349static int parse_linerange(struct ddebug_query *query, const char *first)
350{
351 char *last = strchr(first, '-');
352
353 if (query->first_lineno || query->last_lineno) {
354 pr_err("match-spec: line used 2x\n");
355 return -EINVAL;
356 }
357 if (last)
358 *last++ = '\0';
359 if (parse_lineno(first, &query->first_lineno) < 0)
360 return -EINVAL;
361 if (last) {
362 /* range <first>-<last> */
363 if (parse_lineno(last, &query->last_lineno) < 0)
364 return -EINVAL;
365
366 /* special case for last lineno not specified */
367 if (query->last_lineno == 0)
368 query->last_lineno = UINT_MAX;
369
370 if (query->last_lineno < query->first_lineno) {
371 pr_err("last-line:%d < 1st-line:%d\n",
372 query->last_lineno,
373 query->first_lineno);
374 return -EINVAL;
375 }
376 } else {
377 query->last_lineno = query->first_lineno;
378 }
379 v3pr_info("parsed line %d-%d\n", query->first_lineno,
380 query->last_lineno);
381 return 0;
382}
383
384static int check_set(const char **dest, char *src, char *name)
385{
386 int rc = 0;
387
388 if (*dest) {
389 rc = -EINVAL;
390 pr_err("match-spec:%s val:%s overridden by %s\n",
391 name, *dest, src);
392 }
393 *dest = src;
394 return rc;
395}
396
397/*
398 * Parse words[] as a ddebug query specification, which is a series
399 * of (keyword, value) pairs chosen from these possibilities:
400 *
401 * func <function-name>
402 * file <full-pathname>
403 * file <base-filename>
404 * module <module-name>
405 * format <escaped-string-to-find-in-format>
406 * line <lineno>
407 * line <first-lineno>-<last-lineno> // where either may be empty
408 *
409 * Only 1 of each type is allowed.
410 * Returns 0 on success, <0 on error.
411 */
412static int ddebug_parse_query(char *words[], int nwords,
413 struct ddebug_query *query, const char *modname)
414{
415 unsigned int i;
416 int rc = 0;
417 char *fline;
418
419 /* check we have an even number of words */
420 if (nwords % 2 != 0) {
421 pr_err("expecting pairs of match-spec <value>\n");
422 return -EINVAL;
423 }
424
425 for (i = 0; i < nwords; i += 2) {
426 char *keyword = words[i];
427 char *arg = words[i+1];
428
429 if (!strcmp(keyword, "func")) {
430 rc = check_set(&query->function, arg, "func");
431 } else if (!strcmp(keyword, "file")) {
432 if (check_set(&query->filename, arg, "file"))
433 return -EINVAL;
434
435 /* tail :$info is function or line-range */
436 fline = strchr(query->filename, ':');
437 if (!fline)
438 continue;
439 *fline++ = '\0';
440 if (isalpha(*fline) || *fline == '*' || *fline == '?') {
441 /* take as function name */
442 if (check_set(&query->function, fline, "func"))
443 return -EINVAL;
444 } else {
445 if (parse_linerange(query, fline))
446 return -EINVAL;
447 }
448 } else if (!strcmp(keyword, "module")) {
449 rc = check_set(&query->module, arg, "module");
450 } else if (!strcmp(keyword, "format")) {
451 string_unescape_inplace(arg, UNESCAPE_SPACE |
452 UNESCAPE_OCTAL |
453 UNESCAPE_SPECIAL);
454 rc = check_set(&query->format, arg, "format");
455 } else if (!strcmp(keyword, "line")) {
456 if (parse_linerange(query, arg))
457 return -EINVAL;
458 } else if (!strcmp(keyword, "class")) {
459 rc = check_set(&query->class_string, arg, "class");
460 } else {
461 pr_err("unknown keyword \"%s\"\n", keyword);
462 return -EINVAL;
463 }
464 if (rc)
465 return rc;
466 }
467 if (!query->module && modname)
468 /*
469 * support $modname.dyndbg=<multiple queries>, when
470 * not given in the query itself
471 */
472 query->module = modname;
473
474 vpr_info_dq(query, "parsed");
475 return 0;
476}
477
478/*
479 * Parse `str' as a flags specification, format [-+=][p]+.
480 * Sets up *maskp and *flagsp to be used when changing the
481 * flags fields of matched _ddebug's. Returns 0 on success
482 * or <0 on error.
483 */
484static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
485{
486 int op, i;
487
488 switch (*str) {
489 case '+':
490 case '-':
491 case '=':
492 op = *str++;
493 break;
494 default:
495 pr_err("bad flag-op %c, at start of %s\n", *str, str);
496 return -EINVAL;
497 }
498 v3pr_info("op='%c'\n", op);
499
500 for (; *str ; ++str) {
501 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
502 if (*str == opt_array[i].opt_char) {
503 modifiers->flags |= opt_array[i].flag;
504 break;
505 }
506 }
507 if (i < 0) {
508 pr_err("unknown flag '%c'\n", *str);
509 return -EINVAL;
510 }
511 }
512 v3pr_info("flags=0x%x\n", modifiers->flags);
513
514 /* calculate final flags, mask based upon op */
515 switch (op) {
516 case '=':
517 /* modifiers->flags already set */
518 modifiers->mask = 0;
519 break;
520 case '+':
521 modifiers->mask = ~0U;
522 break;
523 case '-':
524 modifiers->mask = ~modifiers->flags;
525 modifiers->flags = 0;
526 break;
527 }
528 v3pr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
529
530 return 0;
531}
532
533static int ddebug_exec_query(char *query_string, const char *modname)
534{
535 struct flag_settings modifiers = {};
536 struct ddebug_query query = {};
537#define MAXWORDS 9
538 int nwords, nfound;
539 char *words[MAXWORDS];
540
541 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
542 if (nwords <= 0) {
543 pr_err("tokenize failed\n");
544 return -EINVAL;
545 }
546 /* check flags 1st (last arg) so query is pairs of spec,val */
547 if (ddebug_parse_flags(words[nwords-1], &modifiers)) {
548 pr_err("flags parse failed\n");
549 return -EINVAL;
550 }
551 if (ddebug_parse_query(words, nwords-1, &query, modname)) {
552 pr_err("query parse failed\n");
553 return -EINVAL;
554 }
555 /* actually go and implement the change */
556 nfound = ddebug_change(&query, &modifiers);
557 vpr_info_dq(&query, nfound ? "applied" : "no-match");
558
559 return nfound;
560}
561
562/* handle multiple queries in query string, continue on error, return
563 last error or number of matching callsites. Module name is either
564 in param (for boot arg) or perhaps in query string.
565*/
566static int ddebug_exec_queries(char *query, const char *modname)
567{
568 char *split;
569 int i, errs = 0, exitcode = 0, rc, nfound = 0;
570
571 for (i = 0; query; query = split) {
572 split = strpbrk(query, ";\n");
573 if (split)
574 *split++ = '\0';
575
576 query = skip_spaces(query);
577 if (!query || !*query || *query == '#')
578 continue;
579
580 vpr_info("query %d: \"%s\" mod:%s\n", i, query, modname ?: "*");
581
582 rc = ddebug_exec_query(query, modname);
583 if (rc < 0) {
584 errs++;
585 exitcode = rc;
586 } else {
587 nfound += rc;
588 }
589 i++;
590 }
591 if (i)
592 v2pr_info("processed %d queries, with %d matches, %d errs\n",
593 i, nfound, errs);
594
595 if (exitcode)
596 return exitcode;
597 return nfound;
598}
599
600/* apply a new bitmap to the sys-knob's current bit-state */
601static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
602 unsigned long *new_bits, unsigned long *old_bits)
603{
604#define QUERY_SIZE 128
605 char query[QUERY_SIZE];
606 const struct ddebug_class_map *map = dcp->map;
607 int matches = 0;
608 int bi, ct;
609
610 v2pr_info("apply: 0x%lx to: 0x%lx\n", *new_bits, *old_bits);
611
612 for (bi = 0; bi < map->length; bi++) {
613 if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
614 continue;
615
616 snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
617 test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
618
619 ct = ddebug_exec_queries(query, NULL);
620 matches += ct;
621
622 v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
623 ct, map->class_names[bi], *new_bits);
624 }
625 return matches;
626}
627
628/* stub to later conditionally add "$module." prefix where not already done */
629#define KP_NAME(kp) kp->name
630
631#define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
632
633/* accept comma-separated-list of [+-] classnames */
634static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp)
635{
636 const struct ddebug_class_param *dcp = kp->arg;
637 const struct ddebug_class_map *map = dcp->map;
638 unsigned long curr_bits, old_bits;
639 char *cl_str, *p, *tmp;
640 int cls_id, totct = 0;
641 bool wanted;
642
643 cl_str = tmp = kstrdup(instr, GFP_KERNEL);
644 p = strchr(cl_str, '\n');
645 if (p)
646 *p = '\0';
647
648 /* start with previously set state-bits, then modify */
649 curr_bits = old_bits = *dcp->bits;
650 vpr_info("\"%s\" > %s:0x%lx\n", cl_str, KP_NAME(kp), curr_bits);
651
652 for (; cl_str; cl_str = p) {
653 p = strchr(cl_str, ',');
654 if (p)
655 *p++ = '\0';
656
657 if (*cl_str == '-') {
658 wanted = false;
659 cl_str++;
660 } else {
661 wanted = true;
662 if (*cl_str == '+')
663 cl_str++;
664 }
665 cls_id = match_string(map->class_names, map->length, cl_str);
666 if (cls_id < 0) {
667 pr_err("%s unknown to %s\n", cl_str, KP_NAME(kp));
668 continue;
669 }
670
671 /* have one or more valid class_ids of one *_NAMES type */
672 switch (map->map_type) {
673 case DD_CLASS_TYPE_DISJOINT_NAMES:
674 /* the +/- pertains to a single bit */
675 if (test_bit(cls_id, &curr_bits) == wanted) {
676 v3pr_info("no change on %s\n", cl_str);
677 continue;
678 }
679 curr_bits ^= BIT(cls_id);
680 totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits);
681 *dcp->bits = curr_bits;
682 v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
683 map->class_names[cls_id]);
684 break;
685 case DD_CLASS_TYPE_LEVEL_NAMES:
686 /* cls_id = N in 0..max. wanted +/- determines N or N-1 */
687 old_bits = CLASSMAP_BITMASK(*dcp->lvl);
688 curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
689
690 totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits);
691 *dcp->lvl = (cls_id + (wanted ? 1 : 0));
692 v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
693 map->class_names[cls_id], old_bits, curr_bits);
694 break;
695 default:
696 pr_err("illegal map-type value %d\n", map->map_type);
697 }
698 }
699 kfree(tmp);
700 vpr_info("total matches: %d\n", totct);
701 return 0;
702}
703
704/**
705 * param_set_dyndbg_classes - class FOO >control
706 * @instr: string echo>d to sysfs, input depends on map_type
707 * @kp: kp->arg has state: bits/lvl, map, map_type
708 *
709 * Enable/disable prdbgs by their class, as given in the arguments to
710 * DECLARE_DYNDBG_CLASSMAP. For LEVEL map-types, enforce relative
711 * levels by bitpos.
712 *
713 * Returns: 0 or <0 if error.
714 */
715int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
716{
717 const struct ddebug_class_param *dcp = kp->arg;
718 const struct ddebug_class_map *map = dcp->map;
719 unsigned long inrep, new_bits, old_bits;
720 int rc, totct = 0;
721
722 switch (map->map_type) {
723
724 case DD_CLASS_TYPE_DISJOINT_NAMES:
725 case DD_CLASS_TYPE_LEVEL_NAMES:
726 /* handle [+-]classnames list separately, we are done here */
727 return param_set_dyndbg_classnames(instr, kp);
728
729 case DD_CLASS_TYPE_DISJOINT_BITS:
730 case DD_CLASS_TYPE_LEVEL_NUM:
731 /* numeric input, accept and fall-thru */
732 rc = kstrtoul(instr, 0, &inrep);
733 if (rc) {
734 pr_err("expecting numeric input: %s > %s\n", instr, KP_NAME(kp));
735 return -EINVAL;
736 }
737 break;
738 default:
739 pr_err("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
740 return -EINVAL;
741 }
742
743 /* only _BITS,_NUM (numeric) map-types get here */
744 switch (map->map_type) {
745 case DD_CLASS_TYPE_DISJOINT_BITS:
746 /* expect bits. mask and warn if too many */
747 if (inrep & ~CLASSMAP_BITMASK(map->length)) {
748 pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
749 KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
750 inrep &= CLASSMAP_BITMASK(map->length);
751 }
752 v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
753 totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits);
754 *dcp->bits = inrep;
755 break;
756 case DD_CLASS_TYPE_LEVEL_NUM:
757 /* input is bitpos, of highest verbosity to be enabled */
758 if (inrep > map->length) {
759 pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
760 KP_NAME(kp), inrep, map->length);
761 inrep = map->length;
762 }
763 old_bits = CLASSMAP_BITMASK(*dcp->lvl);
764 new_bits = CLASSMAP_BITMASK(inrep);
765 v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
766 totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits);
767 *dcp->lvl = inrep;
768 break;
769 default:
770 pr_warn("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
771 }
772 vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
773 return 0;
774}
775EXPORT_SYMBOL(param_set_dyndbg_classes);
776
777/**
778 * param_get_dyndbg_classes - classes reader
779 * @buffer: string description of controlled bits -> classes
780 * @kp: kp->arg has state: bits, map
781 *
782 * Reads last written state, underlying prdbg state may have been
783 * altered by direct >control. Displays 0x for DISJOINT, 0-N for
784 * LEVEL Returns: #chars written or <0 on error
785 */
786int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
787{
788 const struct ddebug_class_param *dcp = kp->arg;
789 const struct ddebug_class_map *map = dcp->map;
790
791 switch (map->map_type) {
792
793 case DD_CLASS_TYPE_DISJOINT_NAMES:
794 case DD_CLASS_TYPE_DISJOINT_BITS:
795 return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
796
797 case DD_CLASS_TYPE_LEVEL_NAMES:
798 case DD_CLASS_TYPE_LEVEL_NUM:
799 return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
800 default:
801 return -1;
802 }
803}
804EXPORT_SYMBOL(param_get_dyndbg_classes);
805
806const struct kernel_param_ops param_ops_dyndbg_classes = {
807 .set = param_set_dyndbg_classes,
808 .get = param_get_dyndbg_classes,
809};
810EXPORT_SYMBOL(param_ops_dyndbg_classes);
811
812#define PREFIX_SIZE 128
813
814static int remaining(int wrote)
815{
816 if (PREFIX_SIZE - wrote > 0)
817 return PREFIX_SIZE - wrote;
818 return 0;
819}
820
821static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
822{
823 int pos_after_tid;
824 int pos = 0;
825
826 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
827 if (in_interrupt())
828 pos += snprintf(buf + pos, remaining(pos), "<intr> ");
829 else
830 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
831 task_pid_vnr(current));
832 }
833 pos_after_tid = pos;
834 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
835 pos += snprintf(buf + pos, remaining(pos), "%s:",
836 desc->modname);
837 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
838 pos += snprintf(buf + pos, remaining(pos), "%s:",
839 desc->function);
840 if (desc->flags & _DPRINTK_FLAGS_INCL_SOURCENAME)
841 pos += snprintf(buf + pos, remaining(pos), "%s:",
842 trim_prefix(desc->filename));
843 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
844 pos += snprintf(buf + pos, remaining(pos), "%d:",
845 desc->lineno);
846 if (pos - pos_after_tid)
847 pos += snprintf(buf + pos, remaining(pos), " ");
848 if (pos >= PREFIX_SIZE)
849 buf[PREFIX_SIZE - 1] = '\0';
850
851 return buf;
852}
853
854static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)
855{
856 if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_ANY))
857 return __dynamic_emit_prefix(desc, buf);
858 return buf;
859}
860
861void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
862{
863 va_list args;
864 struct va_format vaf;
865 char buf[PREFIX_SIZE] = "";
866
867 BUG_ON(!descriptor);
868 BUG_ON(!fmt);
869
870 va_start(args, fmt);
871
872 vaf.fmt = fmt;
873 vaf.va = &args;
874
875 printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
876
877 va_end(args);
878}
879EXPORT_SYMBOL(__dynamic_pr_debug);
880
881void __dynamic_dev_dbg(struct _ddebug *descriptor,
882 const struct device *dev, const char *fmt, ...)
883{
884 struct va_format vaf;
885 va_list args;
886
887 BUG_ON(!descriptor);
888 BUG_ON(!fmt);
889
890 va_start(args, fmt);
891
892 vaf.fmt = fmt;
893 vaf.va = &args;
894
895 if (!dev) {
896 printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
897 } else {
898 char buf[PREFIX_SIZE] = "";
899
900 dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
901 dynamic_emit_prefix(descriptor, buf),
902 dev_driver_string(dev), dev_name(dev),
903 &vaf);
904 }
905
906 va_end(args);
907}
908EXPORT_SYMBOL(__dynamic_dev_dbg);
909
910#ifdef CONFIG_NET
911
912void __dynamic_netdev_dbg(struct _ddebug *descriptor,
913 const struct net_device *dev, const char *fmt, ...)
914{
915 struct va_format vaf;
916 va_list args;
917
918 BUG_ON(!descriptor);
919 BUG_ON(!fmt);
920
921 va_start(args, fmt);
922
923 vaf.fmt = fmt;
924 vaf.va = &args;
925
926 if (dev && dev->dev.parent) {
927 char buf[PREFIX_SIZE] = "";
928
929 dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
930 "%s%s %s %s%s: %pV",
931 dynamic_emit_prefix(descriptor, buf),
932 dev_driver_string(dev->dev.parent),
933 dev_name(dev->dev.parent),
934 netdev_name(dev), netdev_reg_state(dev),
935 &vaf);
936 } else if (dev) {
937 printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
938 netdev_reg_state(dev), &vaf);
939 } else {
940 printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
941 }
942
943 va_end(args);
944}
945EXPORT_SYMBOL(__dynamic_netdev_dbg);
946
947#endif
948
949#if IS_ENABLED(CONFIG_INFINIBAND)
950
951void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
952 const struct ib_device *ibdev, const char *fmt, ...)
953{
954 struct va_format vaf;
955 va_list args;
956
957 va_start(args, fmt);
958
959 vaf.fmt = fmt;
960 vaf.va = &args;
961
962 if (ibdev && ibdev->dev.parent) {
963 char buf[PREFIX_SIZE] = "";
964
965 dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
966 "%s%s %s %s: %pV",
967 dynamic_emit_prefix(descriptor, buf),
968 dev_driver_string(ibdev->dev.parent),
969 dev_name(ibdev->dev.parent),
970 dev_name(&ibdev->dev),
971 &vaf);
972 } else if (ibdev) {
973 printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
974 } else {
975 printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
976 }
977
978 va_end(args);
979}
980EXPORT_SYMBOL(__dynamic_ibdev_dbg);
981
982#endif
983
984/*
985 * Install a noop handler to make dyndbg look like a normal kernel cli param.
986 * This avoids warnings about dyndbg being an unknown cli param when supplied
987 * by a user.
988 */
989static __init int dyndbg_setup(char *str)
990{
991 return 1;
992}
993
994__setup("dyndbg=", dyndbg_setup);
995
996/*
997 * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
998 * command text from userspace, parses and executes it.
999 */
1000#define USER_BUF_PAGE 4096
1001static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
1002 size_t len, loff_t *offp)
1003{
1004 char *tmpbuf;
1005 int ret;
1006
1007 if (len == 0)
1008 return 0;
1009 if (len > USER_BUF_PAGE - 1) {
1010 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
1011 return -E2BIG;
1012 }
1013 tmpbuf = memdup_user_nul(ubuf, len);
1014 if (IS_ERR(tmpbuf))
1015 return PTR_ERR(tmpbuf);
1016 v2pr_info("read %zu bytes from userspace\n", len);
1017
1018 ret = ddebug_exec_queries(tmpbuf, NULL);
1019 kfree(tmpbuf);
1020 if (ret < 0)
1021 return ret;
1022
1023 *offp += len;
1024 return len;
1025}
1026
1027/*
1028 * Set the iterator to point to the first _ddebug object
1029 * and return a pointer to that first object. Returns
1030 * NULL if there are no _ddebugs at all.
1031 */
1032static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
1033{
1034 if (list_empty(&ddebug_tables)) {
1035 iter->table = NULL;
1036 return NULL;
1037 }
1038 iter->table = list_entry(ddebug_tables.next,
1039 struct ddebug_table, link);
1040 iter->idx = iter->table->num_ddebugs;
1041 return &iter->table->ddebugs[--iter->idx];
1042}
1043
1044/*
1045 * Advance the iterator to point to the next _ddebug
1046 * object from the one the iterator currently points at,
1047 * and returns a pointer to the new _ddebug. Returns
1048 * NULL if the iterator has seen all the _ddebugs.
1049 */
1050static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
1051{
1052 if (iter->table == NULL)
1053 return NULL;
1054 if (--iter->idx < 0) {
1055 /* iterate to next table */
1056 if (list_is_last(&iter->table->link, &ddebug_tables)) {
1057 iter->table = NULL;
1058 return NULL;
1059 }
1060 iter->table = list_entry(iter->table->link.next,
1061 struct ddebug_table, link);
1062 iter->idx = iter->table->num_ddebugs;
1063 --iter->idx;
1064 }
1065 return &iter->table->ddebugs[iter->idx];
1066}
1067
1068/*
1069 * Seq_ops start method. Called at the start of every
1070 * read() call from userspace. Takes the ddebug_lock and
1071 * seeks the seq_file's iterator to the given position.
1072 */
1073static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
1074{
1075 struct ddebug_iter *iter = m->private;
1076 struct _ddebug *dp;
1077 int n = *pos;
1078
1079 mutex_lock(&ddebug_lock);
1080
1081 if (!n)
1082 return SEQ_START_TOKEN;
1083 if (n < 0)
1084 return NULL;
1085 dp = ddebug_iter_first(iter);
1086 while (dp != NULL && --n > 0)
1087 dp = ddebug_iter_next(iter);
1088 return dp;
1089}
1090
1091/*
1092 * Seq_ops next method. Called several times within a read()
1093 * call from userspace, with ddebug_lock held. Walks to the
1094 * next _ddebug object with a special case for the header line.
1095 */
1096static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
1097{
1098 struct ddebug_iter *iter = m->private;
1099 struct _ddebug *dp;
1100
1101 if (p == SEQ_START_TOKEN)
1102 dp = ddebug_iter_first(iter);
1103 else
1104 dp = ddebug_iter_next(iter);
1105 ++*pos;
1106 return dp;
1107}
1108
1109#define class_in_range(class_id, map) \
1110 (class_id >= map->base && class_id < map->base + map->length)
1111
1112static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
1113{
1114 struct ddebug_class_map *map;
1115
1116 list_for_each_entry(map, &iter->table->maps, link)
1117 if (class_in_range(dp->class_id, map))
1118 return map->class_names[dp->class_id - map->base];
1119
1120 return NULL;
1121}
1122
1123/*
1124 * Seq_ops show method. Called several times within a read()
1125 * call from userspace, with ddebug_lock held. Formats the
1126 * current _ddebug as a single human-readable line, with a
1127 * special case for the header line.
1128 */
1129static int ddebug_proc_show(struct seq_file *m, void *p)
1130{
1131 struct ddebug_iter *iter = m->private;
1132 struct _ddebug *dp = p;
1133 struct flagsbuf flags;
1134 char const *class;
1135
1136 if (p == SEQ_START_TOKEN) {
1137 seq_puts(m,
1138 "# filename:lineno [module]function flags format\n");
1139 return 0;
1140 }
1141
1142 seq_printf(m, "%s:%u [%s]%s =%s \"",
1143 trim_prefix(dp->filename), dp->lineno,
1144 iter->table->mod_name, dp->function,
1145 ddebug_describe_flags(dp->flags, &flags));
1146 seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
1147 seq_puts(m, "\"");
1148
1149 if (dp->class_id != _DPRINTK_CLASS_DFLT) {
1150 class = ddebug_class_name(iter, dp);
1151 if (class)
1152 seq_printf(m, " class:%s", class);
1153 else
1154 seq_printf(m, " class unknown, _id:%d", dp->class_id);
1155 }
1156 seq_puts(m, "\n");
1157
1158 return 0;
1159}
1160
1161/*
1162 * Seq_ops stop method. Called at the end of each read()
1163 * call from userspace. Drops ddebug_lock.
1164 */
1165static void ddebug_proc_stop(struct seq_file *m, void *p)
1166{
1167 mutex_unlock(&ddebug_lock);
1168}
1169
1170static const struct seq_operations ddebug_proc_seqops = {
1171 .start = ddebug_proc_start,
1172 .next = ddebug_proc_next,
1173 .show = ddebug_proc_show,
1174 .stop = ddebug_proc_stop
1175};
1176
1177static int ddebug_proc_open(struct inode *inode, struct file *file)
1178{
1179 return seq_open_private(file, &ddebug_proc_seqops,
1180 sizeof(struct ddebug_iter));
1181}
1182
1183static const struct file_operations ddebug_proc_fops = {
1184 .owner = THIS_MODULE,
1185 .open = ddebug_proc_open,
1186 .read = seq_read,
1187 .llseek = seq_lseek,
1188 .release = seq_release_private,
1189 .write = ddebug_proc_write
1190};
1191
1192static const struct proc_ops proc_fops = {
1193 .proc_open = ddebug_proc_open,
1194 .proc_read = seq_read,
1195 .proc_lseek = seq_lseek,
1196 .proc_release = seq_release_private,
1197 .proc_write = ddebug_proc_write
1198};
1199
1200static void ddebug_attach_module_classes(struct ddebug_table *dt,
1201 struct ddebug_class_map *classes,
1202 int num_classes)
1203{
1204 struct ddebug_class_map *cm;
1205 int i, j, ct = 0;
1206
1207 for (cm = classes, i = 0; i < num_classes; i++, cm++) {
1208
1209 if (!strcmp(cm->mod_name, dt->mod_name)) {
1210
1211 v2pr_info("class[%d]: module:%s base:%d len:%d ty:%d\n", i,
1212 cm->mod_name, cm->base, cm->length, cm->map_type);
1213
1214 for (j = 0; j < cm->length; j++)
1215 v3pr_info(" %d: %d %s\n", j + cm->base, j,
1216 cm->class_names[j]);
1217
1218 list_add(&cm->link, &dt->maps);
1219 ct++;
1220 }
1221 }
1222 if (ct)
1223 vpr_info("module:%s attached %d classes\n", dt->mod_name, ct);
1224}
1225
1226/*
1227 * Allocate a new ddebug_table for the given module
1228 * and add it to the global list.
1229 */
1230static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
1231{
1232 struct ddebug_table *dt;
1233
1234 v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
1235 if (!di->num_descs) {
1236 v3pr_info(" skip %s\n", modname);
1237 return 0;
1238 }
1239
1240 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
1241 if (dt == NULL) {
1242 pr_err("error adding module: %s\n", modname);
1243 return -ENOMEM;
1244 }
1245 /*
1246 * For built-in modules, name lives in .rodata and is
1247 * immortal. For loaded modules, name points at the name[]
1248 * member of struct module, which lives at least as long as
1249 * this struct ddebug_table.
1250 */
1251 dt->mod_name = modname;
1252 dt->ddebugs = di->descs;
1253 dt->num_ddebugs = di->num_descs;
1254
1255 INIT_LIST_HEAD(&dt->link);
1256 INIT_LIST_HEAD(&dt->maps);
1257
1258 if (di->classes && di->num_classes)
1259 ddebug_attach_module_classes(dt, di->classes, di->num_classes);
1260
1261 mutex_lock(&ddebug_lock);
1262 list_add_tail(&dt->link, &ddebug_tables);
1263 mutex_unlock(&ddebug_lock);
1264
1265 vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
1266 return 0;
1267}
1268
1269/* helper for ddebug_dyndbg_(boot|module)_param_cb */
1270static int ddebug_dyndbg_param_cb(char *param, char *val,
1271 const char *modname, int on_err)
1272{
1273 char *sep;
1274
1275 sep = strchr(param, '.');
1276 if (sep) {
1277 /* needed only for ddebug_dyndbg_boot_param_cb */
1278 *sep = '\0';
1279 modname = param;
1280 param = sep + 1;
1281 }
1282 if (strcmp(param, "dyndbg"))
1283 return on_err; /* determined by caller */
1284
1285 ddebug_exec_queries((val ? val : "+p"), modname);
1286
1287 return 0; /* query failure shouldn't stop module load */
1288}
1289
1290/* handle both dyndbg and $module.dyndbg params at boot */
1291static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
1292 const char *unused, void *arg)
1293{
1294 vpr_info("%s=\"%s\"\n", param, val);
1295 return ddebug_dyndbg_param_cb(param, val, NULL, 0);
1296}
1297
1298/*
1299 * modprobe foo finds foo.params in boot-args, strips "foo.", and
1300 * passes them to load_module(). This callback gets unknown params,
1301 * processes dyndbg params, rejects others.
1302 */
1303int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
1304{
1305 vpr_info("module: %s %s=\"%s\"\n", module, param, val);
1306 return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
1307}
1308
1309static void ddebug_table_free(struct ddebug_table *dt)
1310{
1311 list_del_init(&dt->link);
1312 kfree(dt);
1313}
1314
1315#ifdef CONFIG_MODULES
1316
1317/*
1318 * Called in response to a module being unloaded. Removes
1319 * any ddebug_table's which point at the module.
1320 */
1321static int ddebug_remove_module(const char *mod_name)
1322{
1323 struct ddebug_table *dt, *nextdt;
1324 int ret = -ENOENT;
1325
1326 mutex_lock(&ddebug_lock);
1327 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
1328 if (dt->mod_name == mod_name) {
1329 ddebug_table_free(dt);
1330 ret = 0;
1331 break;
1332 }
1333 }
1334 mutex_unlock(&ddebug_lock);
1335 if (!ret)
1336 v2pr_info("removed module \"%s\"\n", mod_name);
1337 return ret;
1338}
1339
1340static int ddebug_module_notify(struct notifier_block *self, unsigned long val,
1341 void *data)
1342{
1343 struct module *mod = data;
1344 int ret = 0;
1345
1346 switch (val) {
1347 case MODULE_STATE_COMING:
1348 ret = ddebug_add_module(&mod->dyndbg_info, mod->name);
1349 if (ret)
1350 WARN(1, "Failed to allocate memory: dyndbg may not work properly.\n");
1351 break;
1352 case MODULE_STATE_GOING:
1353 ddebug_remove_module(mod->name);
1354 break;
1355 }
1356
1357 return notifier_from_errno(ret);
1358}
1359
1360static struct notifier_block ddebug_module_nb = {
1361 .notifier_call = ddebug_module_notify,
1362 .priority = 0, /* dynamic debug depends on jump label */
1363};
1364
1365#endif /* CONFIG_MODULES */
1366
1367static void ddebug_remove_all_tables(void)
1368{
1369 mutex_lock(&ddebug_lock);
1370 while (!list_empty(&ddebug_tables)) {
1371 struct ddebug_table *dt = list_entry(ddebug_tables.next,
1372 struct ddebug_table,
1373 link);
1374 ddebug_table_free(dt);
1375 }
1376 mutex_unlock(&ddebug_lock);
1377}
1378
1379static __initdata int ddebug_init_success;
1380
1381static int __init dynamic_debug_init_control(void)
1382{
1383 struct proc_dir_entry *procfs_dir;
1384 struct dentry *debugfs_dir;
1385
1386 if (!ddebug_init_success)
1387 return -ENODEV;
1388
1389 /* Create the control file in debugfs if it is enabled */
1390 if (debugfs_initialized()) {
1391 debugfs_dir = debugfs_create_dir("dynamic_debug", NULL);
1392 debugfs_create_file("control", 0644, debugfs_dir, NULL,
1393 &ddebug_proc_fops);
1394 }
1395
1396 /* Also create the control file in procfs */
1397 procfs_dir = proc_mkdir("dynamic_debug", NULL);
1398 if (procfs_dir)
1399 proc_create("control", 0644, procfs_dir, &proc_fops);
1400
1401 return 0;
1402}
1403
1404static int __init dynamic_debug_init(void)
1405{
1406 struct _ddebug *iter, *iter_mod_start;
1407 int ret, i, mod_sites, mod_ct;
1408 const char *modname;
1409 char *cmdline;
1410
1411 struct _ddebug_info di = {
1412 .descs = __start___dyndbg,
1413 .classes = __start___dyndbg_classes,
1414 .num_descs = __stop___dyndbg - __start___dyndbg,
1415 .num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
1416 };
1417
1418#ifdef CONFIG_MODULES
1419 ret = register_module_notifier(&ddebug_module_nb);
1420 if (ret) {
1421 pr_warn("Failed to register dynamic debug module notifier\n");
1422 return ret;
1423 }
1424#endif /* CONFIG_MODULES */
1425
1426 if (&__start___dyndbg == &__stop___dyndbg) {
1427 if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
1428 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1429 return 1;
1430 }
1431 pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
1432 ddebug_init_success = 1;
1433 return 0;
1434 }
1435
1436 iter = iter_mod_start = __start___dyndbg;
1437 modname = iter->modname;
1438 i = mod_sites = mod_ct = 0;
1439
1440 for (; iter < __stop___dyndbg; iter++, i++, mod_sites++) {
1441
1442 if (strcmp(modname, iter->modname)) {
1443 mod_ct++;
1444 di.num_descs = mod_sites;
1445 di.descs = iter_mod_start;
1446 ret = ddebug_add_module(&di, modname);
1447 if (ret)
1448 goto out_err;
1449
1450 mod_sites = 0;
1451 modname = iter->modname;
1452 iter_mod_start = iter;
1453 }
1454 }
1455 di.num_descs = mod_sites;
1456 di.descs = iter_mod_start;
1457 ret = ddebug_add_module(&di, modname);
1458 if (ret)
1459 goto out_err;
1460
1461 ddebug_init_success = 1;
1462 vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg section\n",
1463 i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
1464 (int)((i * sizeof(struct _ddebug)) >> 10));
1465
1466 if (di.num_classes)
1467 v2pr_info(" %d builtin ddebug class-maps\n", di.num_classes);
1468
1469 /* now that ddebug tables are loaded, process all boot args
1470 * again to find and activate queries given in dyndbg params.
1471 * While this has already been done for known boot params, it
1472 * ignored the unknown ones (dyndbg in particular). Reusing
1473 * parse_args avoids ad-hoc parsing. This will also attempt
1474 * to activate queries for not-yet-loaded modules, which is
1475 * slightly noisy if verbose, but harmless.
1476 */
1477 cmdline = kstrdup(saved_command_line, GFP_KERNEL);
1478 parse_args("dyndbg params", cmdline, NULL,
1479 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
1480 kfree(cmdline);
1481 return 0;
1482
1483out_err:
1484 ddebug_remove_all_tables();
1485 return 0;
1486}
1487/* Allow early initialization for boot messages via boot param */
1488early_initcall(dynamic_debug_init);
1489
1490/* Debugfs setup must be done later */
1491fs_initcall(dynamic_debug_init_control);