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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) "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[];
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
65struct flag_settings {
66 unsigned int flags;
67 unsigned int mask;
68};
69
70static DEFINE_MUTEX(ddebug_lock);
71static LIST_HEAD(ddebug_tables);
72static int verbose;
73module_param(verbose, int, 0644);
74
75/* Return the path relative to source root */
76static inline const char *trim_prefix(const char *path)
77{
78 int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
79
80 if (strncmp(path, __FILE__, skip))
81 skip = 0; /* prefix mismatch, don't skip */
82
83 return path + skip;
84}
85
86static struct { unsigned flag:8; char opt_char; } opt_array[] = {
87 { _DPRINTK_FLAGS_PRINT, 'p' },
88 { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
89 { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
90 { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
91 { _DPRINTK_FLAGS_INCL_TID, 't' },
92 { _DPRINTK_FLAGS_NONE, '_' },
93};
94
95struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; };
96
97/* format a string into buf[] which describes the _ddebug's flags */
98static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb)
99{
100 char *p = fb->buf;
101 int i;
102
103 for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
104 if (flags & opt_array[i].flag)
105 *p++ = opt_array[i].opt_char;
106 if (p == fb->buf)
107 *p++ = '_';
108 *p = '\0';
109
110 return fb->buf;
111}
112
113#define vnpr_info(lvl, fmt, ...) \
114do { \
115 if (verbose >= lvl) \
116 pr_info(fmt, ##__VA_ARGS__); \
117} while (0)
118
119#define vpr_info(fmt, ...) vnpr_info(1, fmt, ##__VA_ARGS__)
120#define v2pr_info(fmt, ...) vnpr_info(2, fmt, ##__VA_ARGS__)
121
122static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
123{
124 /* trim any trailing newlines */
125 int fmtlen = 0;
126
127 if (query->format) {
128 fmtlen = strlen(query->format);
129 while (fmtlen && query->format[fmtlen - 1] == '\n')
130 fmtlen--;
131 }
132
133 vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n",
134 msg,
135 query->function ?: "",
136 query->filename ?: "",
137 query->module ?: "",
138 fmtlen, query->format ?: "",
139 query->first_lineno, query->last_lineno);
140}
141
142/*
143 * Search the tables for _ddebug's which match the given `query' and
144 * apply the `flags' and `mask' to them. Returns number of matching
145 * callsites, normally the same as number of changes. If verbose,
146 * logs the changes. Takes ddebug_lock.
147 */
148static int ddebug_change(const struct ddebug_query *query,
149 struct flag_settings *modifiers)
150{
151 int i;
152 struct ddebug_table *dt;
153 unsigned int newflags;
154 unsigned int nfound = 0;
155 struct flagsbuf fbuf;
156
157 /* search for matching ddebugs */
158 mutex_lock(&ddebug_lock);
159 list_for_each_entry(dt, &ddebug_tables, link) {
160
161 /* match against the module name */
162 if (query->module &&
163 !match_wildcard(query->module, dt->mod_name))
164 continue;
165
166 for (i = 0; i < dt->num_ddebugs; i++) {
167 struct _ddebug *dp = &dt->ddebugs[i];
168
169 /* match against the source filename */
170 if (query->filename &&
171 !match_wildcard(query->filename, dp->filename) &&
172 !match_wildcard(query->filename,
173 kbasename(dp->filename)) &&
174 !match_wildcard(query->filename,
175 trim_prefix(dp->filename)))
176 continue;
177
178 /* match against the function */
179 if (query->function &&
180 !match_wildcard(query->function, dp->function))
181 continue;
182
183 /* match against the format */
184 if (query->format) {
185 if (*query->format == '^') {
186 char *p;
187 /* anchored search. match must be at beginning */
188 p = strstr(dp->format, query->format+1);
189 if (p != dp->format)
190 continue;
191 } else if (!strstr(dp->format, query->format))
192 continue;
193 }
194
195 /* match against the line number range */
196 if (query->first_lineno &&
197 dp->lineno < query->first_lineno)
198 continue;
199 if (query->last_lineno &&
200 dp->lineno > query->last_lineno)
201 continue;
202
203 nfound++;
204
205 newflags = (dp->flags & modifiers->mask) | modifiers->flags;
206 if (newflags == dp->flags)
207 continue;
208#ifdef CONFIG_JUMP_LABEL
209 if (dp->flags & _DPRINTK_FLAGS_PRINT) {
210 if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT))
211 static_branch_disable(&dp->key.dd_key_true);
212 } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT)
213 static_branch_enable(&dp->key.dd_key_true);
214#endif
215 dp->flags = newflags;
216 v2pr_info("changed %s:%d [%s]%s =%s\n",
217 trim_prefix(dp->filename), dp->lineno,
218 dt->mod_name, dp->function,
219 ddebug_describe_flags(dp->flags, &fbuf));
220 }
221 }
222 mutex_unlock(&ddebug_lock);
223
224 if (!nfound && verbose)
225 pr_info("no matches for query\n");
226
227 return nfound;
228}
229
230/*
231 * Split the buffer `buf' into space-separated words.
232 * Handles simple " and ' quoting, i.e. without nested,
233 * embedded or escaped \". Return the number of words
234 * or <0 on error.
235 */
236static int ddebug_tokenize(char *buf, char *words[], int maxwords)
237{
238 int nwords = 0;
239
240 while (*buf) {
241 char *end;
242
243 /* Skip leading whitespace */
244 buf = skip_spaces(buf);
245 if (!*buf)
246 break; /* oh, it was trailing whitespace */
247 if (*buf == '#')
248 break; /* token starts comment, skip rest of line */
249
250 /* find `end' of word, whitespace separated or quoted */
251 if (*buf == '"' || *buf == '\'') {
252 int quote = *buf++;
253 for (end = buf; *end && *end != quote; end++)
254 ;
255 if (!*end) {
256 pr_err("unclosed quote: %s\n", buf);
257 return -EINVAL; /* unclosed quote */
258 }
259 } else {
260 for (end = buf; *end && !isspace(*end); end++)
261 ;
262 BUG_ON(end == buf);
263 }
264
265 /* `buf' is start of word, `end' is one past its end */
266 if (nwords == maxwords) {
267 pr_err("too many words, legal max <=%d\n", maxwords);
268 return -EINVAL; /* ran out of words[] before bytes */
269 }
270 if (*end)
271 *end++ = '\0'; /* terminate the word */
272 words[nwords++] = buf;
273 buf = end;
274 }
275
276 if (verbose) {
277 int i;
278 pr_info("split into words:");
279 for (i = 0; i < nwords; i++)
280 pr_cont(" \"%s\"", words[i]);
281 pr_cont("\n");
282 }
283
284 return nwords;
285}
286
287/*
288 * Parse a single line number. Note that the empty string ""
289 * is treated as a special case and converted to zero, which
290 * is later treated as a "don't care" value.
291 */
292static inline int parse_lineno(const char *str, unsigned int *val)
293{
294 BUG_ON(str == NULL);
295 if (*str == '\0') {
296 *val = 0;
297 return 0;
298 }
299 if (kstrtouint(str, 10, val) < 0) {
300 pr_err("bad line-number: %s\n", str);
301 return -EINVAL;
302 }
303 return 0;
304}
305
306static int parse_linerange(struct ddebug_query *query, const char *first)
307{
308 char *last = strchr(first, '-');
309
310 if (query->first_lineno || query->last_lineno) {
311 pr_err("match-spec: line used 2x\n");
312 return -EINVAL;
313 }
314 if (last)
315 *last++ = '\0';
316 if (parse_lineno(first, &query->first_lineno) < 0)
317 return -EINVAL;
318 if (last) {
319 /* range <first>-<last> */
320 if (parse_lineno(last, &query->last_lineno) < 0)
321 return -EINVAL;
322
323 /* special case for last lineno not specified */
324 if (query->last_lineno == 0)
325 query->last_lineno = UINT_MAX;
326
327 if (query->last_lineno < query->first_lineno) {
328 pr_err("last-line:%d < 1st-line:%d\n",
329 query->last_lineno,
330 query->first_lineno);
331 return -EINVAL;
332 }
333 } else {
334 query->last_lineno = query->first_lineno;
335 }
336 vpr_info("parsed line %d-%d\n", query->first_lineno,
337 query->last_lineno);
338 return 0;
339}
340
341static int check_set(const char **dest, char *src, char *name)
342{
343 int rc = 0;
344
345 if (*dest) {
346 rc = -EINVAL;
347 pr_err("match-spec:%s val:%s overridden by %s\n",
348 name, *dest, src);
349 }
350 *dest = src;
351 return rc;
352}
353
354/*
355 * Parse words[] as a ddebug query specification, which is a series
356 * of (keyword, value) pairs chosen from these possibilities:
357 *
358 * func <function-name>
359 * file <full-pathname>
360 * file <base-filename>
361 * module <module-name>
362 * format <escaped-string-to-find-in-format>
363 * line <lineno>
364 * line <first-lineno>-<last-lineno> // where either may be empty
365 *
366 * Only 1 of each type is allowed.
367 * Returns 0 on success, <0 on error.
368 */
369static int ddebug_parse_query(char *words[], int nwords,
370 struct ddebug_query *query, const char *modname)
371{
372 unsigned int i;
373 int rc = 0;
374 char *fline;
375
376 /* check we have an even number of words */
377 if (nwords % 2 != 0) {
378 pr_err("expecting pairs of match-spec <value>\n");
379 return -EINVAL;
380 }
381
382 if (modname)
383 /* support $modname.dyndbg=<multiple queries> */
384 query->module = modname;
385
386 for (i = 0; i < nwords; i += 2) {
387 char *keyword = words[i];
388 char *arg = words[i+1];
389
390 if (!strcmp(keyword, "func")) {
391 rc = check_set(&query->function, arg, "func");
392 } else if (!strcmp(keyword, "file")) {
393 if (check_set(&query->filename, arg, "file"))
394 return -EINVAL;
395
396 /* tail :$info is function or line-range */
397 fline = strchr(query->filename, ':');
398 if (!fline)
399 continue;
400 *fline++ = '\0';
401 if (isalpha(*fline) || *fline == '*' || *fline == '?') {
402 /* take as function name */
403 if (check_set(&query->function, fline, "func"))
404 return -EINVAL;
405 } else {
406 if (parse_linerange(query, fline))
407 return -EINVAL;
408 }
409 } else if (!strcmp(keyword, "module")) {
410 rc = check_set(&query->module, arg, "module");
411 } else if (!strcmp(keyword, "format")) {
412 string_unescape_inplace(arg, UNESCAPE_SPACE |
413 UNESCAPE_OCTAL |
414 UNESCAPE_SPECIAL);
415 rc = check_set(&query->format, arg, "format");
416 } else if (!strcmp(keyword, "line")) {
417 if (parse_linerange(query, arg))
418 return -EINVAL;
419 } else {
420 pr_err("unknown keyword \"%s\"\n", keyword);
421 return -EINVAL;
422 }
423 if (rc)
424 return rc;
425 }
426 vpr_info_dq(query, "parsed");
427 return 0;
428}
429
430/*
431 * Parse `str' as a flags specification, format [-+=][p]+.
432 * Sets up *maskp and *flagsp to be used when changing the
433 * flags fields of matched _ddebug's. Returns 0 on success
434 * or <0 on error.
435 */
436static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
437{
438 int op, i;
439
440 switch (*str) {
441 case '+':
442 case '-':
443 case '=':
444 op = *str++;
445 break;
446 default:
447 pr_err("bad flag-op %c, at start of %s\n", *str, str);
448 return -EINVAL;
449 }
450 vpr_info("op='%c'\n", op);
451
452 for (; *str ; ++str) {
453 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
454 if (*str == opt_array[i].opt_char) {
455 modifiers->flags |= opt_array[i].flag;
456 break;
457 }
458 }
459 if (i < 0) {
460 pr_err("unknown flag '%c'\n", *str);
461 return -EINVAL;
462 }
463 }
464 vpr_info("flags=0x%x\n", modifiers->flags);
465
466 /* calculate final flags, mask based upon op */
467 switch (op) {
468 case '=':
469 /* modifiers->flags already set */
470 modifiers->mask = 0;
471 break;
472 case '+':
473 modifiers->mask = ~0U;
474 break;
475 case '-':
476 modifiers->mask = ~modifiers->flags;
477 modifiers->flags = 0;
478 break;
479 }
480 vpr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
481
482 return 0;
483}
484
485static int ddebug_exec_query(char *query_string, const char *modname)
486{
487 struct flag_settings modifiers = {};
488 struct ddebug_query query = {};
489#define MAXWORDS 9
490 int nwords, nfound;
491 char *words[MAXWORDS];
492
493 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
494 if (nwords <= 0) {
495 pr_err("tokenize failed\n");
496 return -EINVAL;
497 }
498 /* check flags 1st (last arg) so query is pairs of spec,val */
499 if (ddebug_parse_flags(words[nwords-1], &modifiers)) {
500 pr_err("flags parse failed\n");
501 return -EINVAL;
502 }
503 if (ddebug_parse_query(words, nwords-1, &query, modname)) {
504 pr_err("query parse failed\n");
505 return -EINVAL;
506 }
507 /* actually go and implement the change */
508 nfound = ddebug_change(&query, &modifiers);
509 vpr_info_dq(&query, nfound ? "applied" : "no-match");
510
511 return nfound;
512}
513
514/* handle multiple queries in query string, continue on error, return
515 last error or number of matching callsites. Module name is either
516 in param (for boot arg) or perhaps in query string.
517*/
518static int ddebug_exec_queries(char *query, const char *modname)
519{
520 char *split;
521 int i, errs = 0, exitcode = 0, rc, nfound = 0;
522
523 for (i = 0; query; query = split) {
524 split = strpbrk(query, ";\n");
525 if (split)
526 *split++ = '\0';
527
528 query = skip_spaces(query);
529 if (!query || !*query || *query == '#')
530 continue;
531
532 vpr_info("query %d: \"%s\"\n", i, query);
533
534 rc = ddebug_exec_query(query, modname);
535 if (rc < 0) {
536 errs++;
537 exitcode = rc;
538 } else {
539 nfound += rc;
540 }
541 i++;
542 }
543 vpr_info("processed %d queries, with %d matches, %d errs\n",
544 i, nfound, errs);
545
546 if (exitcode)
547 return exitcode;
548 return nfound;
549}
550
551/**
552 * dynamic_debug_exec_queries - select and change dynamic-debug prints
553 * @query: query-string described in admin-guide/dynamic-debug-howto
554 * @modname: string containing module name, usually &module.mod_name
555 *
556 * This uses the >/proc/dynamic_debug/control reader, allowing module
557 * authors to modify their dynamic-debug callsites. The modname is
558 * canonically struct module.mod_name, but can also be null or a
559 * module-wildcard, for example: "drm*".
560 */
561int dynamic_debug_exec_queries(const char *query, const char *modname)
562{
563 int rc;
564 char *qry; /* writable copy of query */
565
566 if (!query) {
567 pr_err("non-null query/command string expected\n");
568 return -EINVAL;
569 }
570 qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL);
571 if (!qry)
572 return -ENOMEM;
573
574 rc = ddebug_exec_queries(qry, modname);
575 kfree(qry);
576 return rc;
577}
578EXPORT_SYMBOL_GPL(dynamic_debug_exec_queries);
579
580#define PREFIX_SIZE 64
581
582static int remaining(int wrote)
583{
584 if (PREFIX_SIZE - wrote > 0)
585 return PREFIX_SIZE - wrote;
586 return 0;
587}
588
589static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
590{
591 int pos_after_tid;
592 int pos = 0;
593
594 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
595 if (in_interrupt())
596 pos += snprintf(buf + pos, remaining(pos), "<intr> ");
597 else
598 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
599 task_pid_vnr(current));
600 }
601 pos_after_tid = pos;
602 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
603 pos += snprintf(buf + pos, remaining(pos), "%s:",
604 desc->modname);
605 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
606 pos += snprintf(buf + pos, remaining(pos), "%s:",
607 desc->function);
608 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
609 pos += snprintf(buf + pos, remaining(pos), "%d:",
610 desc->lineno);
611 if (pos - pos_after_tid)
612 pos += snprintf(buf + pos, remaining(pos), " ");
613 if (pos >= PREFIX_SIZE)
614 buf[PREFIX_SIZE - 1] = '\0';
615
616 return buf;
617}
618
619static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)
620{
621 if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_ANY))
622 return __dynamic_emit_prefix(desc, buf);
623 return buf;
624}
625
626void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
627{
628 va_list args;
629 struct va_format vaf;
630 char buf[PREFIX_SIZE] = "";
631
632 BUG_ON(!descriptor);
633 BUG_ON(!fmt);
634
635 va_start(args, fmt);
636
637 vaf.fmt = fmt;
638 vaf.va = &args;
639
640 printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
641
642 va_end(args);
643}
644EXPORT_SYMBOL(__dynamic_pr_debug);
645
646void __dynamic_dev_dbg(struct _ddebug *descriptor,
647 const struct device *dev, const char *fmt, ...)
648{
649 struct va_format vaf;
650 va_list args;
651
652 BUG_ON(!descriptor);
653 BUG_ON(!fmt);
654
655 va_start(args, fmt);
656
657 vaf.fmt = fmt;
658 vaf.va = &args;
659
660 if (!dev) {
661 printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
662 } else {
663 char buf[PREFIX_SIZE] = "";
664
665 dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
666 dynamic_emit_prefix(descriptor, buf),
667 dev_driver_string(dev), dev_name(dev),
668 &vaf);
669 }
670
671 va_end(args);
672}
673EXPORT_SYMBOL(__dynamic_dev_dbg);
674
675#ifdef CONFIG_NET
676
677void __dynamic_netdev_dbg(struct _ddebug *descriptor,
678 const struct net_device *dev, const char *fmt, ...)
679{
680 struct va_format vaf;
681 va_list args;
682
683 BUG_ON(!descriptor);
684 BUG_ON(!fmt);
685
686 va_start(args, fmt);
687
688 vaf.fmt = fmt;
689 vaf.va = &args;
690
691 if (dev && dev->dev.parent) {
692 char buf[PREFIX_SIZE] = "";
693
694 dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
695 "%s%s %s %s%s: %pV",
696 dynamic_emit_prefix(descriptor, buf),
697 dev_driver_string(dev->dev.parent),
698 dev_name(dev->dev.parent),
699 netdev_name(dev), netdev_reg_state(dev),
700 &vaf);
701 } else if (dev) {
702 printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
703 netdev_reg_state(dev), &vaf);
704 } else {
705 printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
706 }
707
708 va_end(args);
709}
710EXPORT_SYMBOL(__dynamic_netdev_dbg);
711
712#endif
713
714#if IS_ENABLED(CONFIG_INFINIBAND)
715
716void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
717 const struct ib_device *ibdev, const char *fmt, ...)
718{
719 struct va_format vaf;
720 va_list args;
721
722 va_start(args, fmt);
723
724 vaf.fmt = fmt;
725 vaf.va = &args;
726
727 if (ibdev && ibdev->dev.parent) {
728 char buf[PREFIX_SIZE] = "";
729
730 dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
731 "%s%s %s %s: %pV",
732 dynamic_emit_prefix(descriptor, buf),
733 dev_driver_string(ibdev->dev.parent),
734 dev_name(ibdev->dev.parent),
735 dev_name(&ibdev->dev),
736 &vaf);
737 } else if (ibdev) {
738 printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
739 } else {
740 printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
741 }
742
743 va_end(args);
744}
745EXPORT_SYMBOL(__dynamic_ibdev_dbg);
746
747#endif
748
749#define DDEBUG_STRING_SIZE 1024
750static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
751
752static __init int ddebug_setup_query(char *str)
753{
754 if (strlen(str) >= DDEBUG_STRING_SIZE) {
755 pr_warn("ddebug boot param string too large\n");
756 return 0;
757 }
758 strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
759 return 1;
760}
761
762__setup("ddebug_query=", ddebug_setup_query);
763
764/*
765 * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
766 * command text from userspace, parses and executes it.
767 */
768#define USER_BUF_PAGE 4096
769static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
770 size_t len, loff_t *offp)
771{
772 char *tmpbuf;
773 int ret;
774
775 if (len == 0)
776 return 0;
777 if (len > USER_BUF_PAGE - 1) {
778 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
779 return -E2BIG;
780 }
781 tmpbuf = memdup_user_nul(ubuf, len);
782 if (IS_ERR(tmpbuf))
783 return PTR_ERR(tmpbuf);
784 vpr_info("read %d bytes from userspace\n", (int)len);
785
786 ret = ddebug_exec_queries(tmpbuf, NULL);
787 kfree(tmpbuf);
788 if (ret < 0)
789 return ret;
790
791 *offp += len;
792 return len;
793}
794
795/*
796 * Set the iterator to point to the first _ddebug object
797 * and return a pointer to that first object. Returns
798 * NULL if there are no _ddebugs at all.
799 */
800static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
801{
802 if (list_empty(&ddebug_tables)) {
803 iter->table = NULL;
804 iter->idx = 0;
805 return NULL;
806 }
807 iter->table = list_entry(ddebug_tables.next,
808 struct ddebug_table, link);
809 iter->idx = 0;
810 return &iter->table->ddebugs[iter->idx];
811}
812
813/*
814 * Advance the iterator to point to the next _ddebug
815 * object from the one the iterator currently points at,
816 * and returns a pointer to the new _ddebug. Returns
817 * NULL if the iterator has seen all the _ddebugs.
818 */
819static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
820{
821 if (iter->table == NULL)
822 return NULL;
823 if (++iter->idx == iter->table->num_ddebugs) {
824 /* iterate to next table */
825 iter->idx = 0;
826 if (list_is_last(&iter->table->link, &ddebug_tables)) {
827 iter->table = NULL;
828 return NULL;
829 }
830 iter->table = list_entry(iter->table->link.next,
831 struct ddebug_table, link);
832 }
833 return &iter->table->ddebugs[iter->idx];
834}
835
836/*
837 * Seq_ops start method. Called at the start of every
838 * read() call from userspace. Takes the ddebug_lock and
839 * seeks the seq_file's iterator to the given position.
840 */
841static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
842{
843 struct ddebug_iter *iter = m->private;
844 struct _ddebug *dp;
845 int n = *pos;
846
847 mutex_lock(&ddebug_lock);
848
849 if (!n)
850 return SEQ_START_TOKEN;
851 if (n < 0)
852 return NULL;
853 dp = ddebug_iter_first(iter);
854 while (dp != NULL && --n > 0)
855 dp = ddebug_iter_next(iter);
856 return dp;
857}
858
859/*
860 * Seq_ops next method. Called several times within a read()
861 * call from userspace, with ddebug_lock held. Walks to the
862 * next _ddebug object with a special case for the header line.
863 */
864static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
865{
866 struct ddebug_iter *iter = m->private;
867 struct _ddebug *dp;
868
869 if (p == SEQ_START_TOKEN)
870 dp = ddebug_iter_first(iter);
871 else
872 dp = ddebug_iter_next(iter);
873 ++*pos;
874 return dp;
875}
876
877/*
878 * Seq_ops show method. Called several times within a read()
879 * call from userspace, with ddebug_lock held. Formats the
880 * current _ddebug as a single human-readable line, with a
881 * special case for the header line.
882 */
883static int ddebug_proc_show(struct seq_file *m, void *p)
884{
885 struct ddebug_iter *iter = m->private;
886 struct _ddebug *dp = p;
887 struct flagsbuf flags;
888
889 if (p == SEQ_START_TOKEN) {
890 seq_puts(m,
891 "# filename:lineno [module]function flags format\n");
892 return 0;
893 }
894
895 seq_printf(m, "%s:%u [%s]%s =%s \"",
896 trim_prefix(dp->filename), dp->lineno,
897 iter->table->mod_name, dp->function,
898 ddebug_describe_flags(dp->flags, &flags));
899 seq_escape(m, dp->format, "\t\r\n\"");
900 seq_puts(m, "\"\n");
901
902 return 0;
903}
904
905/*
906 * Seq_ops stop method. Called at the end of each read()
907 * call from userspace. Drops ddebug_lock.
908 */
909static void ddebug_proc_stop(struct seq_file *m, void *p)
910{
911 mutex_unlock(&ddebug_lock);
912}
913
914static const struct seq_operations ddebug_proc_seqops = {
915 .start = ddebug_proc_start,
916 .next = ddebug_proc_next,
917 .show = ddebug_proc_show,
918 .stop = ddebug_proc_stop
919};
920
921static int ddebug_proc_open(struct inode *inode, struct file *file)
922{
923 return seq_open_private(file, &ddebug_proc_seqops,
924 sizeof(struct ddebug_iter));
925}
926
927static const struct file_operations ddebug_proc_fops = {
928 .owner = THIS_MODULE,
929 .open = ddebug_proc_open,
930 .read = seq_read,
931 .llseek = seq_lseek,
932 .release = seq_release_private,
933 .write = ddebug_proc_write
934};
935
936static const struct proc_ops proc_fops = {
937 .proc_open = ddebug_proc_open,
938 .proc_read = seq_read,
939 .proc_lseek = seq_lseek,
940 .proc_release = seq_release_private,
941 .proc_write = ddebug_proc_write
942};
943
944/*
945 * Allocate a new ddebug_table for the given module
946 * and add it to the global list.
947 */
948int ddebug_add_module(struct _ddebug *tab, unsigned int n,
949 const char *name)
950{
951 struct ddebug_table *dt;
952
953 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
954 if (dt == NULL) {
955 pr_err("error adding module: %s\n", name);
956 return -ENOMEM;
957 }
958 /*
959 * For built-in modules, name lives in .rodata and is
960 * immortal. For loaded modules, name points at the name[]
961 * member of struct module, which lives at least as long as
962 * this struct ddebug_table.
963 */
964 dt->mod_name = name;
965 dt->num_ddebugs = n;
966 dt->ddebugs = tab;
967
968 mutex_lock(&ddebug_lock);
969 list_add(&dt->link, &ddebug_tables);
970 mutex_unlock(&ddebug_lock);
971
972 v2pr_info("%3u debug prints in module %s\n", n, dt->mod_name);
973 return 0;
974}
975
976/* helper for ddebug_dyndbg_(boot|module)_param_cb */
977static int ddebug_dyndbg_param_cb(char *param, char *val,
978 const char *modname, int on_err)
979{
980 char *sep;
981
982 sep = strchr(param, '.');
983 if (sep) {
984 /* needed only for ddebug_dyndbg_boot_param_cb */
985 *sep = '\0';
986 modname = param;
987 param = sep + 1;
988 }
989 if (strcmp(param, "dyndbg"))
990 return on_err; /* determined by caller */
991
992 ddebug_exec_queries((val ? val : "+p"), modname);
993
994 return 0; /* query failure shouldn't stop module load */
995}
996
997/* handle both dyndbg and $module.dyndbg params at boot */
998static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
999 const char *unused, void *arg)
1000{
1001 vpr_info("%s=\"%s\"\n", param, val);
1002 return ddebug_dyndbg_param_cb(param, val, NULL, 0);
1003}
1004
1005/*
1006 * modprobe foo finds foo.params in boot-args, strips "foo.", and
1007 * passes them to load_module(). This callback gets unknown params,
1008 * processes dyndbg params, rejects others.
1009 */
1010int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
1011{
1012 vpr_info("module: %s %s=\"%s\"\n", module, param, val);
1013 return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
1014}
1015
1016static void ddebug_table_free(struct ddebug_table *dt)
1017{
1018 list_del_init(&dt->link);
1019 kfree(dt);
1020}
1021
1022/*
1023 * Called in response to a module being unloaded. Removes
1024 * any ddebug_table's which point at the module.
1025 */
1026int ddebug_remove_module(const char *mod_name)
1027{
1028 struct ddebug_table *dt, *nextdt;
1029 int ret = -ENOENT;
1030
1031 v2pr_info("removing module \"%s\"\n", mod_name);
1032
1033 mutex_lock(&ddebug_lock);
1034 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
1035 if (dt->mod_name == mod_name) {
1036 ddebug_table_free(dt);
1037 ret = 0;
1038 break;
1039 }
1040 }
1041 mutex_unlock(&ddebug_lock);
1042 return ret;
1043}
1044
1045static void ddebug_remove_all_tables(void)
1046{
1047 mutex_lock(&ddebug_lock);
1048 while (!list_empty(&ddebug_tables)) {
1049 struct ddebug_table *dt = list_entry(ddebug_tables.next,
1050 struct ddebug_table,
1051 link);
1052 ddebug_table_free(dt);
1053 }
1054 mutex_unlock(&ddebug_lock);
1055}
1056
1057static __initdata int ddebug_init_success;
1058
1059static int __init dynamic_debug_init_control(void)
1060{
1061 struct proc_dir_entry *procfs_dir;
1062 struct dentry *debugfs_dir;
1063
1064 if (!ddebug_init_success)
1065 return -ENODEV;
1066
1067 /* Create the control file in debugfs if it is enabled */
1068 if (debugfs_initialized()) {
1069 debugfs_dir = debugfs_create_dir("dynamic_debug", NULL);
1070 debugfs_create_file("control", 0644, debugfs_dir, NULL,
1071 &ddebug_proc_fops);
1072 }
1073
1074 /* Also create the control file in procfs */
1075 procfs_dir = proc_mkdir("dynamic_debug", NULL);
1076 if (procfs_dir)
1077 proc_create("control", 0644, procfs_dir, &proc_fops);
1078
1079 return 0;
1080}
1081
1082static int __init dynamic_debug_init(void)
1083{
1084 struct _ddebug *iter, *iter_start;
1085 const char *modname = NULL;
1086 char *cmdline;
1087 int ret = 0;
1088 int n = 0, entries = 0, modct = 0;
1089
1090 if (&__start___dyndbg == &__stop___dyndbg) {
1091 if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
1092 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1093 return 1;
1094 }
1095 pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
1096 ddebug_init_success = 1;
1097 return 0;
1098 }
1099 iter = __start___dyndbg;
1100 modname = iter->modname;
1101 iter_start = iter;
1102 for (; iter < __stop___dyndbg; iter++) {
1103 entries++;
1104 if (strcmp(modname, iter->modname)) {
1105 modct++;
1106 ret = ddebug_add_module(iter_start, n, modname);
1107 if (ret)
1108 goto out_err;
1109 n = 0;
1110 modname = iter->modname;
1111 iter_start = iter;
1112 }
1113 n++;
1114 }
1115 ret = ddebug_add_module(iter_start, n, modname);
1116 if (ret)
1117 goto out_err;
1118
1119 ddebug_init_success = 1;
1120 vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg section\n",
1121 entries, modct, (int)((modct * sizeof(struct ddebug_table)) >> 10),
1122 (int)((entries * sizeof(struct _ddebug)) >> 10));
1123
1124 /* apply ddebug_query boot param, dont unload tables on err */
1125 if (ddebug_setup_string[0] != '\0') {
1126 pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n");
1127 ret = ddebug_exec_queries(ddebug_setup_string, NULL);
1128 if (ret < 0)
1129 pr_warn("Invalid ddebug boot param %s\n",
1130 ddebug_setup_string);
1131 else
1132 pr_info("%d changes by ddebug_query\n", ret);
1133 }
1134 /* now that ddebug tables are loaded, process all boot args
1135 * again to find and activate queries given in dyndbg params.
1136 * While this has already been done for known boot params, it
1137 * ignored the unknown ones (dyndbg in particular). Reusing
1138 * parse_args avoids ad-hoc parsing. This will also attempt
1139 * to activate queries for not-yet-loaded modules, which is
1140 * slightly noisy if verbose, but harmless.
1141 */
1142 cmdline = kstrdup(saved_command_line, GFP_KERNEL);
1143 parse_args("dyndbg params", cmdline, NULL,
1144 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
1145 kfree(cmdline);
1146 return 0;
1147
1148out_err:
1149 ddebug_remove_all_tables();
1150 return 0;
1151}
1152/* Allow early initialization for boot messages via boot param */
1153early_initcall(dynamic_debug_init);
1154
1155/* Debugfs setup must be done later */
1156fs_initcall(dynamic_debug_init_control);
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);