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
42 extern struct _ddebug __start___dyndbg[];
43 extern struct _ddebug __stop___dyndbg[];
44 extern struct ddebug_class_map __start___dyndbg_classes[];
45 extern struct ddebug_class_map __stop___dyndbg_classes[];
46
47 struct ddebug_table {
48 struct list_head link, maps;
49 const char *mod_name;
50 unsigned int num_ddebugs;
51 struct _ddebug *ddebugs;
52 };
53
54 struct 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
63 struct ddebug_iter {
64 struct ddebug_table *table;
65 int idx;
66 };
67
68 struct flag_settings {
69 unsigned int flags;
70 unsigned int mask;
71 };
72
73 static DEFINE_MUTEX(ddebug_lock);
74 static LIST_HEAD(ddebug_tables);
75 static int verbose;
76 module_param(verbose, int, 0644);
77 MODULE_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 */
trim_prefix(const char * path)81 static 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
91 static 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
101 struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; };
102
103 /* format a string into buf[] which describes the _ddebug's flags */
ddebug_describe_flags(unsigned int flags,struct flagsbuf * fb)104 static 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, ...) \
120 do { \
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
vpr_info_dq(const struct ddebug_query * query,const char * msg)130 static 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
ddebug_find_valid_class(struct ddebug_table const * dt,const char * class_string,int * class_id)150 static 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 */
ddebug_change(const struct ddebug_query * query,struct flag_settings * modifiers)174 static 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 */
ddebug_tokenize(char * buf,char * words[],int maxwords)279 static 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 if (end == buf) {
306 pr_err("parse err after word:%d=%s\n", nwords,
307 nwords ? words[nwords - 1] : "<none>");
308 return -EINVAL;
309 }
310 }
311
312 /* `buf' is start of word, `end' is one past its end */
313 if (nwords == maxwords) {
314 pr_err("too many words, legal max <=%d\n", maxwords);
315 return -EINVAL; /* ran out of words[] before bytes */
316 }
317 if (*end)
318 *end++ = '\0'; /* terminate the word */
319 words[nwords++] = buf;
320 buf = end;
321 }
322
323 if (verbose >= 3) {
324 int i;
325 pr_info("split into words:");
326 for (i = 0; i < nwords; i++)
327 pr_cont(" \"%s\"", words[i]);
328 pr_cont("\n");
329 }
330
331 return nwords;
332 }
333
334 /*
335 * Parse a single line number. Note that the empty string ""
336 * is treated as a special case and converted to zero, which
337 * is later treated as a "don't care" value.
338 */
parse_lineno(const char * str,unsigned int * val)339 static inline int parse_lineno(const char *str, unsigned int *val)
340 {
341 BUG_ON(str == NULL);
342 if (*str == '\0') {
343 *val = 0;
344 return 0;
345 }
346 if (kstrtouint(str, 10, val) < 0) {
347 pr_err("bad line-number: %s\n", str);
348 return -EINVAL;
349 }
350 return 0;
351 }
352
parse_linerange(struct ddebug_query * query,const char * first)353 static int parse_linerange(struct ddebug_query *query, const char *first)
354 {
355 char *last = strchr(first, '-');
356
357 if (query->first_lineno || query->last_lineno) {
358 pr_err("match-spec: line used 2x\n");
359 return -EINVAL;
360 }
361 if (last)
362 *last++ = '\0';
363 if (parse_lineno(first, &query->first_lineno) < 0)
364 return -EINVAL;
365 if (last) {
366 /* range <first>-<last> */
367 if (parse_lineno(last, &query->last_lineno) < 0)
368 return -EINVAL;
369
370 /* special case for last lineno not specified */
371 if (query->last_lineno == 0)
372 query->last_lineno = UINT_MAX;
373
374 if (query->last_lineno < query->first_lineno) {
375 pr_err("last-line:%d < 1st-line:%d\n",
376 query->last_lineno,
377 query->first_lineno);
378 return -EINVAL;
379 }
380 } else {
381 query->last_lineno = query->first_lineno;
382 }
383 v3pr_info("parsed line %d-%d\n", query->first_lineno,
384 query->last_lineno);
385 return 0;
386 }
387
check_set(const char ** dest,char * src,char * name)388 static int check_set(const char **dest, char *src, char *name)
389 {
390 int rc = 0;
391
392 if (*dest) {
393 rc = -EINVAL;
394 pr_err("match-spec:%s val:%s overridden by %s\n",
395 name, *dest, src);
396 }
397 *dest = src;
398 return rc;
399 }
400
401 /*
402 * Parse words[] as a ddebug query specification, which is a series
403 * of (keyword, value) pairs chosen from these possibilities:
404 *
405 * func <function-name>
406 * file <full-pathname>
407 * file <base-filename>
408 * module <module-name>
409 * format <escaped-string-to-find-in-format>
410 * line <lineno>
411 * line <first-lineno>-<last-lineno> // where either may be empty
412 *
413 * Only 1 of each type is allowed.
414 * Returns 0 on success, <0 on error.
415 */
ddebug_parse_query(char * words[],int nwords,struct ddebug_query * query,const char * modname)416 static int ddebug_parse_query(char *words[], int nwords,
417 struct ddebug_query *query, const char *modname)
418 {
419 unsigned int i;
420 int rc = 0;
421 char *fline;
422
423 /* check we have an even number of words */
424 if (nwords % 2 != 0) {
425 pr_err("expecting pairs of match-spec <value>\n");
426 return -EINVAL;
427 }
428
429 for (i = 0; i < nwords; i += 2) {
430 char *keyword = words[i];
431 char *arg = words[i+1];
432
433 if (!strcmp(keyword, "func")) {
434 rc = check_set(&query->function, arg, "func");
435 } else if (!strcmp(keyword, "file")) {
436 if (check_set(&query->filename, arg, "file"))
437 return -EINVAL;
438
439 /* tail :$info is function or line-range */
440 fline = strchr(query->filename, ':');
441 if (!fline)
442 continue;
443 *fline++ = '\0';
444 if (isalpha(*fline) || *fline == '*' || *fline == '?') {
445 /* take as function name */
446 if (check_set(&query->function, fline, "func"))
447 return -EINVAL;
448 } else {
449 if (parse_linerange(query, fline))
450 return -EINVAL;
451 }
452 } else if (!strcmp(keyword, "module")) {
453 rc = check_set(&query->module, arg, "module");
454 } else if (!strcmp(keyword, "format")) {
455 string_unescape_inplace(arg, UNESCAPE_SPACE |
456 UNESCAPE_OCTAL |
457 UNESCAPE_SPECIAL);
458 rc = check_set(&query->format, arg, "format");
459 } else if (!strcmp(keyword, "line")) {
460 if (parse_linerange(query, arg))
461 return -EINVAL;
462 } else if (!strcmp(keyword, "class")) {
463 rc = check_set(&query->class_string, arg, "class");
464 } else {
465 pr_err("unknown keyword \"%s\"\n", keyword);
466 return -EINVAL;
467 }
468 if (rc)
469 return rc;
470 }
471 if (!query->module && modname)
472 /*
473 * support $modname.dyndbg=<multiple queries>, when
474 * not given in the query itself
475 */
476 query->module = modname;
477
478 vpr_info_dq(query, "parsed");
479 return 0;
480 }
481
482 /*
483 * Parse `str' as a flags specification, format [-+=][p]+.
484 * Sets up *maskp and *flagsp to be used when changing the
485 * flags fields of matched _ddebug's. Returns 0 on success
486 * or <0 on error.
487 */
ddebug_parse_flags(const char * str,struct flag_settings * modifiers)488 static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
489 {
490 int op, i;
491
492 switch (*str) {
493 case '+':
494 case '-':
495 case '=':
496 op = *str++;
497 break;
498 default:
499 pr_err("bad flag-op %c, at start of %s\n", *str, str);
500 return -EINVAL;
501 }
502 v3pr_info("op='%c'\n", op);
503
504 for (; *str ; ++str) {
505 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
506 if (*str == opt_array[i].opt_char) {
507 modifiers->flags |= opt_array[i].flag;
508 break;
509 }
510 }
511 if (i < 0) {
512 pr_err("unknown flag '%c'\n", *str);
513 return -EINVAL;
514 }
515 }
516 v3pr_info("flags=0x%x\n", modifiers->flags);
517
518 /* calculate final flags, mask based upon op */
519 switch (op) {
520 case '=':
521 /* modifiers->flags already set */
522 modifiers->mask = 0;
523 break;
524 case '+':
525 modifiers->mask = ~0U;
526 break;
527 case '-':
528 modifiers->mask = ~modifiers->flags;
529 modifiers->flags = 0;
530 break;
531 }
532 v3pr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
533
534 return 0;
535 }
536
ddebug_exec_query(char * query_string,const char * modname)537 static int ddebug_exec_query(char *query_string, const char *modname)
538 {
539 struct flag_settings modifiers = {};
540 struct ddebug_query query = {};
541 #define MAXWORDS 9
542 int nwords, nfound;
543 char *words[MAXWORDS];
544
545 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
546 if (nwords <= 0) {
547 pr_err("tokenize failed\n");
548 return -EINVAL;
549 }
550 /* check flags 1st (last arg) so query is pairs of spec,val */
551 if (ddebug_parse_flags(words[nwords-1], &modifiers)) {
552 pr_err("flags parse failed\n");
553 return -EINVAL;
554 }
555 if (ddebug_parse_query(words, nwords-1, &query, modname)) {
556 pr_err("query parse failed\n");
557 return -EINVAL;
558 }
559 /* actually go and implement the change */
560 nfound = ddebug_change(&query, &modifiers);
561 vpr_info_dq(&query, nfound ? "applied" : "no-match");
562
563 return nfound;
564 }
565
566 /* handle multiple queries in query string, continue on error, return
567 last error or number of matching callsites. Module name is either
568 in param (for boot arg) or perhaps in query string.
569 */
ddebug_exec_queries(char * query,const char * modname)570 static int ddebug_exec_queries(char *query, const char *modname)
571 {
572 char *split;
573 int i, errs = 0, exitcode = 0, rc, nfound = 0;
574
575 for (i = 0; query; query = split) {
576 split = strpbrk(query, ";\n");
577 if (split)
578 *split++ = '\0';
579
580 query = skip_spaces(query);
581 if (!query || !*query || *query == '#')
582 continue;
583
584 vpr_info("query %d: \"%s\" mod:%s\n", i, query, modname ?: "*");
585
586 rc = ddebug_exec_query(query, modname);
587 if (rc < 0) {
588 errs++;
589 exitcode = rc;
590 } else {
591 nfound += rc;
592 }
593 i++;
594 }
595 if (i)
596 v2pr_info("processed %d queries, with %d matches, %d errs\n",
597 i, nfound, errs);
598
599 if (exitcode)
600 return exitcode;
601 return nfound;
602 }
603
604 /* apply a new bitmap to the sys-knob's current bit-state */
ddebug_apply_class_bitmap(const struct ddebug_class_param * dcp,unsigned long * new_bits,unsigned long * old_bits)605 static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
606 unsigned long *new_bits, unsigned long *old_bits)
607 {
608 #define QUERY_SIZE 128
609 char query[QUERY_SIZE];
610 const struct ddebug_class_map *map = dcp->map;
611 int matches = 0;
612 int bi, ct;
613
614 v2pr_info("apply: 0x%lx to: 0x%lx\n", *new_bits, *old_bits);
615
616 for (bi = 0; bi < map->length; bi++) {
617 if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
618 continue;
619
620 snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
621 test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
622
623 ct = ddebug_exec_queries(query, NULL);
624 matches += ct;
625
626 v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
627 ct, map->class_names[bi], *new_bits);
628 }
629 return matches;
630 }
631
632 /* stub to later conditionally add "$module." prefix where not already done */
633 #define KP_NAME(kp) kp->name
634
635 #define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
636
637 /* accept comma-separated-list of [+-] classnames */
param_set_dyndbg_classnames(const char * instr,const struct kernel_param * kp)638 static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp)
639 {
640 const struct ddebug_class_param *dcp = kp->arg;
641 const struct ddebug_class_map *map = dcp->map;
642 unsigned long curr_bits, old_bits;
643 char *cl_str, *p, *tmp;
644 int cls_id, totct = 0;
645 bool wanted;
646
647 cl_str = tmp = kstrdup_and_replace(instr, '\n', '\0', GFP_KERNEL);
648 if (!tmp)
649 return -ENOMEM;
650
651 /* start with previously set state-bits, then modify */
652 curr_bits = old_bits = *dcp->bits;
653 vpr_info("\"%s\" > %s:0x%lx\n", cl_str, KP_NAME(kp), curr_bits);
654
655 for (; cl_str; cl_str = p) {
656 p = strchr(cl_str, ',');
657 if (p)
658 *p++ = '\0';
659
660 if (*cl_str == '-') {
661 wanted = false;
662 cl_str++;
663 } else {
664 wanted = true;
665 if (*cl_str == '+')
666 cl_str++;
667 }
668 cls_id = match_string(map->class_names, map->length, cl_str);
669 if (cls_id < 0) {
670 pr_err("%s unknown to %s\n", cl_str, KP_NAME(kp));
671 continue;
672 }
673
674 /* have one or more valid class_ids of one *_NAMES type */
675 switch (map->map_type) {
676 case DD_CLASS_TYPE_DISJOINT_NAMES:
677 /* the +/- pertains to a single bit */
678 if (test_bit(cls_id, &curr_bits) == wanted) {
679 v3pr_info("no change on %s\n", cl_str);
680 continue;
681 }
682 curr_bits ^= BIT(cls_id);
683 totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits);
684 *dcp->bits = curr_bits;
685 v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
686 map->class_names[cls_id]);
687 break;
688 case DD_CLASS_TYPE_LEVEL_NAMES:
689 /* cls_id = N in 0..max. wanted +/- determines N or N-1 */
690 old_bits = CLASSMAP_BITMASK(*dcp->lvl);
691 curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
692
693 totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits);
694 *dcp->lvl = (cls_id + (wanted ? 1 : 0));
695 v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
696 map->class_names[cls_id], old_bits, curr_bits);
697 break;
698 default:
699 pr_err("illegal map-type value %d\n", map->map_type);
700 }
701 }
702 kfree(tmp);
703 vpr_info("total matches: %d\n", totct);
704 return 0;
705 }
706
707 /**
708 * param_set_dyndbg_classes - class FOO >control
709 * @instr: string echo>d to sysfs, input depends on map_type
710 * @kp: kp->arg has state: bits/lvl, map, map_type
711 *
712 * Enable/disable prdbgs by their class, as given in the arguments to
713 * DECLARE_DYNDBG_CLASSMAP. For LEVEL map-types, enforce relative
714 * levels by bitpos.
715 *
716 * Returns: 0 or <0 if error.
717 */
param_set_dyndbg_classes(const char * instr,const struct kernel_param * kp)718 int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
719 {
720 const struct ddebug_class_param *dcp = kp->arg;
721 const struct ddebug_class_map *map = dcp->map;
722 unsigned long inrep, new_bits, old_bits;
723 int rc, totct = 0;
724
725 switch (map->map_type) {
726
727 case DD_CLASS_TYPE_DISJOINT_NAMES:
728 case DD_CLASS_TYPE_LEVEL_NAMES:
729 /* handle [+-]classnames list separately, we are done here */
730 return param_set_dyndbg_classnames(instr, kp);
731
732 case DD_CLASS_TYPE_DISJOINT_BITS:
733 case DD_CLASS_TYPE_LEVEL_NUM:
734 /* numeric input, accept and fall-thru */
735 rc = kstrtoul(instr, 0, &inrep);
736 if (rc) {
737 pr_err("expecting numeric input: %s > %s\n", instr, KP_NAME(kp));
738 return -EINVAL;
739 }
740 break;
741 default:
742 pr_err("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
743 return -EINVAL;
744 }
745
746 /* only _BITS,_NUM (numeric) map-types get here */
747 switch (map->map_type) {
748 case DD_CLASS_TYPE_DISJOINT_BITS:
749 /* expect bits. mask and warn if too many */
750 if (inrep & ~CLASSMAP_BITMASK(map->length)) {
751 pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
752 KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
753 inrep &= CLASSMAP_BITMASK(map->length);
754 }
755 v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
756 totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits);
757 *dcp->bits = inrep;
758 break;
759 case DD_CLASS_TYPE_LEVEL_NUM:
760 /* input is bitpos, of highest verbosity to be enabled */
761 if (inrep > map->length) {
762 pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
763 KP_NAME(kp), inrep, map->length);
764 inrep = map->length;
765 }
766 old_bits = CLASSMAP_BITMASK(*dcp->lvl);
767 new_bits = CLASSMAP_BITMASK(inrep);
768 v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
769 totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits);
770 *dcp->lvl = inrep;
771 break;
772 default:
773 pr_warn("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
774 }
775 vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
776 return 0;
777 }
778 EXPORT_SYMBOL(param_set_dyndbg_classes);
779
780 /**
781 * param_get_dyndbg_classes - classes reader
782 * @buffer: string description of controlled bits -> classes
783 * @kp: kp->arg has state: bits, map
784 *
785 * Reads last written state, underlying prdbg state may have been
786 * altered by direct >control. Displays 0x for DISJOINT, 0-N for
787 * LEVEL Returns: #chars written or <0 on error
788 */
param_get_dyndbg_classes(char * buffer,const struct kernel_param * kp)789 int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
790 {
791 const struct ddebug_class_param *dcp = kp->arg;
792 const struct ddebug_class_map *map = dcp->map;
793
794 switch (map->map_type) {
795
796 case DD_CLASS_TYPE_DISJOINT_NAMES:
797 case DD_CLASS_TYPE_DISJOINT_BITS:
798 return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
799
800 case DD_CLASS_TYPE_LEVEL_NAMES:
801 case DD_CLASS_TYPE_LEVEL_NUM:
802 return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
803 default:
804 return -1;
805 }
806 }
807 EXPORT_SYMBOL(param_get_dyndbg_classes);
808
809 const struct kernel_param_ops param_ops_dyndbg_classes = {
810 .set = param_set_dyndbg_classes,
811 .get = param_get_dyndbg_classes,
812 };
813 EXPORT_SYMBOL(param_ops_dyndbg_classes);
814
815 #define PREFIX_SIZE 128
816
remaining(int wrote)817 static int remaining(int wrote)
818 {
819 if (PREFIX_SIZE - wrote > 0)
820 return PREFIX_SIZE - wrote;
821 return 0;
822 }
823
__dynamic_emit_prefix(const struct _ddebug * desc,char * buf)824 static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
825 {
826 int pos_after_tid;
827 int pos = 0;
828
829 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
830 if (in_interrupt())
831 pos += snprintf(buf + pos, remaining(pos), "<intr> ");
832 else
833 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
834 task_pid_vnr(current));
835 }
836 pos_after_tid = pos;
837 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
838 pos += snprintf(buf + pos, remaining(pos), "%s:",
839 desc->modname);
840 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
841 pos += snprintf(buf + pos, remaining(pos), "%s:",
842 desc->function);
843 if (desc->flags & _DPRINTK_FLAGS_INCL_SOURCENAME)
844 pos += snprintf(buf + pos, remaining(pos), "%s:",
845 trim_prefix(desc->filename));
846 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
847 pos += snprintf(buf + pos, remaining(pos), "%d:",
848 desc->lineno);
849 if (pos - pos_after_tid)
850 pos += snprintf(buf + pos, remaining(pos), " ");
851 if (pos >= PREFIX_SIZE)
852 buf[PREFIX_SIZE - 1] = '\0';
853
854 return buf;
855 }
856
dynamic_emit_prefix(struct _ddebug * desc,char * buf)857 static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)
858 {
859 if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_ANY))
860 return __dynamic_emit_prefix(desc, buf);
861 return buf;
862 }
863
__dynamic_pr_debug(struct _ddebug * descriptor,const char * fmt,...)864 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
865 {
866 va_list args;
867 struct va_format vaf;
868 char buf[PREFIX_SIZE] = "";
869
870 BUG_ON(!descriptor);
871 BUG_ON(!fmt);
872
873 va_start(args, fmt);
874
875 vaf.fmt = fmt;
876 vaf.va = &args;
877
878 printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
879
880 va_end(args);
881 }
882 EXPORT_SYMBOL(__dynamic_pr_debug);
883
__dynamic_dev_dbg(struct _ddebug * descriptor,const struct device * dev,const char * fmt,...)884 void __dynamic_dev_dbg(struct _ddebug *descriptor,
885 const struct device *dev, const char *fmt, ...)
886 {
887 struct va_format vaf;
888 va_list args;
889
890 BUG_ON(!descriptor);
891 BUG_ON(!fmt);
892
893 va_start(args, fmt);
894
895 vaf.fmt = fmt;
896 vaf.va = &args;
897
898 if (!dev) {
899 printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
900 } else {
901 char buf[PREFIX_SIZE] = "";
902
903 dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
904 dynamic_emit_prefix(descriptor, buf),
905 dev_driver_string(dev), dev_name(dev),
906 &vaf);
907 }
908
909 va_end(args);
910 }
911 EXPORT_SYMBOL(__dynamic_dev_dbg);
912
913 #ifdef CONFIG_NET
914
__dynamic_netdev_dbg(struct _ddebug * descriptor,const struct net_device * dev,const char * fmt,...)915 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
916 const struct net_device *dev, const char *fmt, ...)
917 {
918 struct va_format vaf;
919 va_list args;
920
921 BUG_ON(!descriptor);
922 BUG_ON(!fmt);
923
924 va_start(args, fmt);
925
926 vaf.fmt = fmt;
927 vaf.va = &args;
928
929 if (dev && dev->dev.parent) {
930 char buf[PREFIX_SIZE] = "";
931
932 dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
933 "%s%s %s %s%s: %pV",
934 dynamic_emit_prefix(descriptor, buf),
935 dev_driver_string(dev->dev.parent),
936 dev_name(dev->dev.parent),
937 netdev_name(dev), netdev_reg_state(dev),
938 &vaf);
939 } else if (dev) {
940 printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
941 netdev_reg_state(dev), &vaf);
942 } else {
943 printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
944 }
945
946 va_end(args);
947 }
948 EXPORT_SYMBOL(__dynamic_netdev_dbg);
949
950 #endif
951
952 #if IS_ENABLED(CONFIG_INFINIBAND)
953
__dynamic_ibdev_dbg(struct _ddebug * descriptor,const struct ib_device * ibdev,const char * fmt,...)954 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
955 const struct ib_device *ibdev, const char *fmt, ...)
956 {
957 struct va_format vaf;
958 va_list args;
959
960 va_start(args, fmt);
961
962 vaf.fmt = fmt;
963 vaf.va = &args;
964
965 if (ibdev && ibdev->dev.parent) {
966 char buf[PREFIX_SIZE] = "";
967
968 dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
969 "%s%s %s %s: %pV",
970 dynamic_emit_prefix(descriptor, buf),
971 dev_driver_string(ibdev->dev.parent),
972 dev_name(ibdev->dev.parent),
973 dev_name(&ibdev->dev),
974 &vaf);
975 } else if (ibdev) {
976 printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
977 } else {
978 printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
979 }
980
981 va_end(args);
982 }
983 EXPORT_SYMBOL(__dynamic_ibdev_dbg);
984
985 #endif
986
987 /*
988 * Install a noop handler to make dyndbg look like a normal kernel cli param.
989 * This avoids warnings about dyndbg being an unknown cli param when supplied
990 * by a user.
991 */
dyndbg_setup(char * str)992 static __init int dyndbg_setup(char *str)
993 {
994 return 1;
995 }
996
997 __setup("dyndbg=", dyndbg_setup);
998
999 /*
1000 * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
1001 * command text from userspace, parses and executes it.
1002 */
1003 #define USER_BUF_PAGE 4096
ddebug_proc_write(struct file * file,const char __user * ubuf,size_t len,loff_t * offp)1004 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
1005 size_t len, loff_t *offp)
1006 {
1007 char *tmpbuf;
1008 int ret;
1009
1010 if (len == 0)
1011 return 0;
1012 if (len > USER_BUF_PAGE - 1) {
1013 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
1014 return -E2BIG;
1015 }
1016 tmpbuf = memdup_user_nul(ubuf, len);
1017 if (IS_ERR(tmpbuf))
1018 return PTR_ERR(tmpbuf);
1019 v2pr_info("read %zu bytes from userspace\n", len);
1020
1021 ret = ddebug_exec_queries(tmpbuf, NULL);
1022 kfree(tmpbuf);
1023 if (ret < 0)
1024 return ret;
1025
1026 *offp += len;
1027 return len;
1028 }
1029
1030 /*
1031 * Set the iterator to point to the first _ddebug object
1032 * and return a pointer to that first object. Returns
1033 * NULL if there are no _ddebugs at all.
1034 */
ddebug_iter_first(struct ddebug_iter * iter)1035 static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
1036 {
1037 if (list_empty(&ddebug_tables)) {
1038 iter->table = NULL;
1039 return NULL;
1040 }
1041 iter->table = list_entry(ddebug_tables.next,
1042 struct ddebug_table, link);
1043 iter->idx = iter->table->num_ddebugs;
1044 return &iter->table->ddebugs[--iter->idx];
1045 }
1046
1047 /*
1048 * Advance the iterator to point to the next _ddebug
1049 * object from the one the iterator currently points at,
1050 * and returns a pointer to the new _ddebug. Returns
1051 * NULL if the iterator has seen all the _ddebugs.
1052 */
ddebug_iter_next(struct ddebug_iter * iter)1053 static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
1054 {
1055 if (iter->table == NULL)
1056 return NULL;
1057 if (--iter->idx < 0) {
1058 /* iterate to next table */
1059 if (list_is_last(&iter->table->link, &ddebug_tables)) {
1060 iter->table = NULL;
1061 return NULL;
1062 }
1063 iter->table = list_entry(iter->table->link.next,
1064 struct ddebug_table, link);
1065 iter->idx = iter->table->num_ddebugs;
1066 --iter->idx;
1067 }
1068 return &iter->table->ddebugs[iter->idx];
1069 }
1070
1071 /*
1072 * Seq_ops start method. Called at the start of every
1073 * read() call from userspace. Takes the ddebug_lock and
1074 * seeks the seq_file's iterator to the given position.
1075 */
ddebug_proc_start(struct seq_file * m,loff_t * pos)1076 static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
1077 {
1078 struct ddebug_iter *iter = m->private;
1079 struct _ddebug *dp;
1080 int n = *pos;
1081
1082 mutex_lock(&ddebug_lock);
1083
1084 if (!n)
1085 return SEQ_START_TOKEN;
1086 if (n < 0)
1087 return NULL;
1088 dp = ddebug_iter_first(iter);
1089 while (dp != NULL && --n > 0)
1090 dp = ddebug_iter_next(iter);
1091 return dp;
1092 }
1093
1094 /*
1095 * Seq_ops next method. Called several times within a read()
1096 * call from userspace, with ddebug_lock held. Walks to the
1097 * next _ddebug object with a special case for the header line.
1098 */
ddebug_proc_next(struct seq_file * m,void * p,loff_t * pos)1099 static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
1100 {
1101 struct ddebug_iter *iter = m->private;
1102 struct _ddebug *dp;
1103
1104 if (p == SEQ_START_TOKEN)
1105 dp = ddebug_iter_first(iter);
1106 else
1107 dp = ddebug_iter_next(iter);
1108 ++*pos;
1109 return dp;
1110 }
1111
1112 #define class_in_range(class_id, map) \
1113 (class_id >= map->base && class_id < map->base + map->length)
1114
ddebug_class_name(struct ddebug_iter * iter,struct _ddebug * dp)1115 static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
1116 {
1117 struct ddebug_class_map *map;
1118
1119 list_for_each_entry(map, &iter->table->maps, link)
1120 if (class_in_range(dp->class_id, map))
1121 return map->class_names[dp->class_id - map->base];
1122
1123 return NULL;
1124 }
1125
1126 /*
1127 * Seq_ops show method. Called several times within a read()
1128 * call from userspace, with ddebug_lock held. Formats the
1129 * current _ddebug as a single human-readable line, with a
1130 * special case for the header line.
1131 */
ddebug_proc_show(struct seq_file * m,void * p)1132 static int ddebug_proc_show(struct seq_file *m, void *p)
1133 {
1134 struct ddebug_iter *iter = m->private;
1135 struct _ddebug *dp = p;
1136 struct flagsbuf flags;
1137 char const *class;
1138
1139 if (p == SEQ_START_TOKEN) {
1140 seq_puts(m,
1141 "# filename:lineno [module]function flags format\n");
1142 return 0;
1143 }
1144
1145 seq_printf(m, "%s:%u [%s]%s =%s \"",
1146 trim_prefix(dp->filename), dp->lineno,
1147 iter->table->mod_name, dp->function,
1148 ddebug_describe_flags(dp->flags, &flags));
1149 seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
1150 seq_puts(m, "\"");
1151
1152 if (dp->class_id != _DPRINTK_CLASS_DFLT) {
1153 class = ddebug_class_name(iter, dp);
1154 if (class)
1155 seq_printf(m, " class:%s", class);
1156 else
1157 seq_printf(m, " class unknown, _id:%d", dp->class_id);
1158 }
1159 seq_puts(m, "\n");
1160
1161 return 0;
1162 }
1163
1164 /*
1165 * Seq_ops stop method. Called at the end of each read()
1166 * call from userspace. Drops ddebug_lock.
1167 */
ddebug_proc_stop(struct seq_file * m,void * p)1168 static void ddebug_proc_stop(struct seq_file *m, void *p)
1169 {
1170 mutex_unlock(&ddebug_lock);
1171 }
1172
1173 static const struct seq_operations ddebug_proc_seqops = {
1174 .start = ddebug_proc_start,
1175 .next = ddebug_proc_next,
1176 .show = ddebug_proc_show,
1177 .stop = ddebug_proc_stop
1178 };
1179
ddebug_proc_open(struct inode * inode,struct file * file)1180 static int ddebug_proc_open(struct inode *inode, struct file *file)
1181 {
1182 return seq_open_private(file, &ddebug_proc_seqops,
1183 sizeof(struct ddebug_iter));
1184 }
1185
1186 static const struct file_operations ddebug_proc_fops = {
1187 .owner = THIS_MODULE,
1188 .open = ddebug_proc_open,
1189 .read = seq_read,
1190 .llseek = seq_lseek,
1191 .release = seq_release_private,
1192 .write = ddebug_proc_write
1193 };
1194
1195 static const struct proc_ops proc_fops = {
1196 .proc_open = ddebug_proc_open,
1197 .proc_read = seq_read,
1198 .proc_lseek = seq_lseek,
1199 .proc_release = seq_release_private,
1200 .proc_write = ddebug_proc_write
1201 };
1202
ddebug_attach_module_classes(struct ddebug_table * dt,struct ddebug_class_map * classes,int num_classes)1203 static void ddebug_attach_module_classes(struct ddebug_table *dt,
1204 struct ddebug_class_map *classes,
1205 int num_classes)
1206 {
1207 struct ddebug_class_map *cm;
1208 int i, j, ct = 0;
1209
1210 for (cm = classes, i = 0; i < num_classes; i++, cm++) {
1211
1212 if (!strcmp(cm->mod_name, dt->mod_name)) {
1213
1214 v2pr_info("class[%d]: module:%s base:%d len:%d ty:%d\n", i,
1215 cm->mod_name, cm->base, cm->length, cm->map_type);
1216
1217 for (j = 0; j < cm->length; j++)
1218 v3pr_info(" %d: %d %s\n", j + cm->base, j,
1219 cm->class_names[j]);
1220
1221 list_add(&cm->link, &dt->maps);
1222 ct++;
1223 }
1224 }
1225 if (ct)
1226 vpr_info("module:%s attached %d classes\n", dt->mod_name, ct);
1227 }
1228
1229 /*
1230 * Allocate a new ddebug_table for the given module
1231 * and add it to the global list.
1232 */
ddebug_add_module(struct _ddebug_info * di,const char * modname)1233 static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
1234 {
1235 struct ddebug_table *dt;
1236
1237 v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
1238 if (!di->num_descs) {
1239 v3pr_info(" skip %s\n", modname);
1240 return 0;
1241 }
1242
1243 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
1244 if (dt == NULL) {
1245 pr_err("error adding module: %s\n", modname);
1246 return -ENOMEM;
1247 }
1248 /*
1249 * For built-in modules, name lives in .rodata and is
1250 * immortal. For loaded modules, name points at the name[]
1251 * member of struct module, which lives at least as long as
1252 * this struct ddebug_table.
1253 */
1254 dt->mod_name = modname;
1255 dt->ddebugs = di->descs;
1256 dt->num_ddebugs = di->num_descs;
1257
1258 INIT_LIST_HEAD(&dt->link);
1259 INIT_LIST_HEAD(&dt->maps);
1260
1261 if (di->classes && di->num_classes)
1262 ddebug_attach_module_classes(dt, di->classes, di->num_classes);
1263
1264 mutex_lock(&ddebug_lock);
1265 list_add_tail(&dt->link, &ddebug_tables);
1266 mutex_unlock(&ddebug_lock);
1267
1268 vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
1269 return 0;
1270 }
1271
1272 /* helper for ddebug_dyndbg_(boot|module)_param_cb */
ddebug_dyndbg_param_cb(char * param,char * val,const char * modname,int on_err)1273 static int ddebug_dyndbg_param_cb(char *param, char *val,
1274 const char *modname, int on_err)
1275 {
1276 char *sep;
1277
1278 sep = strchr(param, '.');
1279 if (sep) {
1280 /* needed only for ddebug_dyndbg_boot_param_cb */
1281 *sep = '\0';
1282 modname = param;
1283 param = sep + 1;
1284 }
1285 if (strcmp(param, "dyndbg"))
1286 return on_err; /* determined by caller */
1287
1288 ddebug_exec_queries((val ? val : "+p"), modname);
1289
1290 return 0; /* query failure shouldn't stop module load */
1291 }
1292
1293 /* handle both dyndbg and $module.dyndbg params at boot */
ddebug_dyndbg_boot_param_cb(char * param,char * val,const char * unused,void * arg)1294 static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
1295 const char *unused, void *arg)
1296 {
1297 vpr_info("%s=\"%s\"\n", param, val);
1298 return ddebug_dyndbg_param_cb(param, val, NULL, 0);
1299 }
1300
1301 /*
1302 * modprobe foo finds foo.params in boot-args, strips "foo.", and
1303 * passes them to load_module(). This callback gets unknown params,
1304 * processes dyndbg params, rejects others.
1305 */
ddebug_dyndbg_module_param_cb(char * param,char * val,const char * module)1306 int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
1307 {
1308 vpr_info("module: %s %s=\"%s\"\n", module, param, val);
1309 return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
1310 }
1311
ddebug_table_free(struct ddebug_table * dt)1312 static void ddebug_table_free(struct ddebug_table *dt)
1313 {
1314 list_del_init(&dt->link);
1315 kfree(dt);
1316 }
1317
1318 #ifdef CONFIG_MODULES
1319
1320 /*
1321 * Called in response to a module being unloaded. Removes
1322 * any ddebug_table's which point at the module.
1323 */
ddebug_remove_module(const char * mod_name)1324 static int ddebug_remove_module(const char *mod_name)
1325 {
1326 struct ddebug_table *dt, *nextdt;
1327 int ret = -ENOENT;
1328
1329 mutex_lock(&ddebug_lock);
1330 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
1331 if (dt->mod_name == mod_name) {
1332 ddebug_table_free(dt);
1333 ret = 0;
1334 break;
1335 }
1336 }
1337 mutex_unlock(&ddebug_lock);
1338 if (!ret)
1339 v2pr_info("removed module \"%s\"\n", mod_name);
1340 return ret;
1341 }
1342
ddebug_module_notify(struct notifier_block * self,unsigned long val,void * data)1343 static int ddebug_module_notify(struct notifier_block *self, unsigned long val,
1344 void *data)
1345 {
1346 struct module *mod = data;
1347 int ret = 0;
1348
1349 switch (val) {
1350 case MODULE_STATE_COMING:
1351 ret = ddebug_add_module(&mod->dyndbg_info, mod->name);
1352 if (ret)
1353 WARN(1, "Failed to allocate memory: dyndbg may not work properly.\n");
1354 break;
1355 case MODULE_STATE_GOING:
1356 ddebug_remove_module(mod->name);
1357 break;
1358 }
1359
1360 return notifier_from_errno(ret);
1361 }
1362
1363 static struct notifier_block ddebug_module_nb = {
1364 .notifier_call = ddebug_module_notify,
1365 .priority = 0, /* dynamic debug depends on jump label */
1366 };
1367
1368 #endif /* CONFIG_MODULES */
1369
ddebug_remove_all_tables(void)1370 static void ddebug_remove_all_tables(void)
1371 {
1372 mutex_lock(&ddebug_lock);
1373 while (!list_empty(&ddebug_tables)) {
1374 struct ddebug_table *dt = list_entry(ddebug_tables.next,
1375 struct ddebug_table,
1376 link);
1377 ddebug_table_free(dt);
1378 }
1379 mutex_unlock(&ddebug_lock);
1380 }
1381
1382 static __initdata int ddebug_init_success;
1383
dynamic_debug_init_control(void)1384 static int __init dynamic_debug_init_control(void)
1385 {
1386 struct proc_dir_entry *procfs_dir;
1387 struct dentry *debugfs_dir;
1388
1389 if (!ddebug_init_success)
1390 return -ENODEV;
1391
1392 /* Create the control file in debugfs if it is enabled */
1393 if (debugfs_initialized()) {
1394 debugfs_dir = debugfs_create_dir("dynamic_debug", NULL);
1395 debugfs_create_file("control", 0644, debugfs_dir, NULL,
1396 &ddebug_proc_fops);
1397 }
1398
1399 /* Also create the control file in procfs */
1400 procfs_dir = proc_mkdir("dynamic_debug", NULL);
1401 if (procfs_dir)
1402 proc_create("control", 0644, procfs_dir, &proc_fops);
1403
1404 return 0;
1405 }
1406
dynamic_debug_init(void)1407 static int __init dynamic_debug_init(void)
1408 {
1409 struct _ddebug *iter, *iter_mod_start;
1410 int ret, i, mod_sites, mod_ct;
1411 const char *modname;
1412 char *cmdline;
1413
1414 struct _ddebug_info di = {
1415 .descs = __start___dyndbg,
1416 .classes = __start___dyndbg_classes,
1417 .num_descs = __stop___dyndbg - __start___dyndbg,
1418 .num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
1419 };
1420
1421 #ifdef CONFIG_MODULES
1422 ret = register_module_notifier(&ddebug_module_nb);
1423 if (ret) {
1424 pr_warn("Failed to register dynamic debug module notifier\n");
1425 return ret;
1426 }
1427 #endif /* CONFIG_MODULES */
1428
1429 if (&__start___dyndbg == &__stop___dyndbg) {
1430 if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
1431 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1432 return 1;
1433 }
1434 pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
1435 ddebug_init_success = 1;
1436 return 0;
1437 }
1438
1439 iter = iter_mod_start = __start___dyndbg;
1440 modname = iter->modname;
1441 i = mod_sites = mod_ct = 0;
1442
1443 for (; iter < __stop___dyndbg; iter++, i++, mod_sites++) {
1444
1445 if (strcmp(modname, iter->modname)) {
1446 mod_ct++;
1447 di.num_descs = mod_sites;
1448 di.descs = iter_mod_start;
1449 ret = ddebug_add_module(&di, modname);
1450 if (ret)
1451 goto out_err;
1452
1453 mod_sites = 0;
1454 modname = iter->modname;
1455 iter_mod_start = iter;
1456 }
1457 }
1458 di.num_descs = mod_sites;
1459 di.descs = iter_mod_start;
1460 ret = ddebug_add_module(&di, modname);
1461 if (ret)
1462 goto out_err;
1463
1464 ddebug_init_success = 1;
1465 vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg section\n",
1466 i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
1467 (int)((i * sizeof(struct _ddebug)) >> 10));
1468
1469 if (di.num_classes)
1470 v2pr_info(" %d builtin ddebug class-maps\n", di.num_classes);
1471
1472 /* now that ddebug tables are loaded, process all boot args
1473 * again to find and activate queries given in dyndbg params.
1474 * While this has already been done for known boot params, it
1475 * ignored the unknown ones (dyndbg in particular). Reusing
1476 * parse_args avoids ad-hoc parsing. This will also attempt
1477 * to activate queries for not-yet-loaded modules, which is
1478 * slightly noisy if verbose, but harmless.
1479 */
1480 cmdline = kstrdup(saved_command_line, GFP_KERNEL);
1481 parse_args("dyndbg params", cmdline, NULL,
1482 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
1483 kfree(cmdline);
1484 return 0;
1485
1486 out_err:
1487 ddebug_remove_all_tables();
1488 return 0;
1489 }
1490 /* Allow early initialization for boot messages via boot param */
1491 early_initcall(dynamic_debug_init);
1492
1493 /* Debugfs setup must be done later */
1494 fs_initcall(dynamic_debug_init_control);
1495