4 * make pr_debug()/dev_dbg() calls runtime configurable based upon their
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>
14 #define pr_fmt(fmt) "dyndbg: " fmt
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>
40 #include <rdma/ib_verbs.h>
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[];
48 struct list_head link, maps;
50 unsigned int num_ddebugs;
51 struct _ddebug *ddebugs;
59 const char *class_string;
60 unsigned int first_lineno, last_lineno;
64 struct ddebug_table *table;
68 struct flag_settings {
73 static DEFINE_MUTEX(ddebug_lock);
74 static LIST_HEAD(ddebug_tables);
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)");
80 /* Return the path relative to source root */
81 static inline const char *trim_prefix(const char *path)
83 int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
85 if (strncmp(path, __FILE__, skip))
86 skip = 0; /* prefix mismatch, don't skip */
91 static 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_LINENO, 'l' },
96 { _DPRINTK_FLAGS_INCL_TID, 't' },
97 { _DPRINTK_FLAGS_NONE, '_' },
100 struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; };
102 /* format a string into buf[] which describes the _ddebug's flags */
103 static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb)
108 for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
109 if (flags & opt_array[i].flag)
110 *p++ = opt_array[i].opt_char;
118 #define vnpr_info(lvl, fmt, ...) \
120 if (verbose >= lvl) \
121 pr_info(fmt, ##__VA_ARGS__); \
124 #define vpr_info(fmt, ...) vnpr_info(1, fmt, ##__VA_ARGS__)
125 #define v2pr_info(fmt, ...) vnpr_info(2, fmt, ##__VA_ARGS__)
126 #define v3pr_info(fmt, ...) vnpr_info(3, fmt, ##__VA_ARGS__)
127 #define v4pr_info(fmt, ...) vnpr_info(4, fmt, ##__VA_ARGS__)
129 static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
131 /* trim any trailing newlines */
135 fmtlen = strlen(query->format);
136 while (fmtlen && query->format[fmtlen - 1] == '\n')
140 v3pr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u class=%s\n",
142 query->function ?: "",
143 query->filename ?: "",
145 fmtlen, query->format ?: "",
146 query->first_lineno, query->last_lineno, query->class_string);
149 static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
150 const char *class_string, int *class_id)
152 struct ddebug_class_map *map;
155 list_for_each_entry(map, &dt->maps, link) {
156 idx = match_string(map->class_names, map->length, class_string);
158 *class_id = idx + map->base;
166 #define __outvar /* filled by callee */
168 * Search the tables for _ddebug's which match the given `query' and
169 * apply the `flags' and `mask' to them. Returns number of matching
170 * callsites, normally the same as number of changes. If verbose,
171 * logs the changes. Takes ddebug_lock.
173 static int ddebug_change(const struct ddebug_query *query,
174 struct flag_settings *modifiers)
177 struct ddebug_table *dt;
178 unsigned int newflags;
179 unsigned int nfound = 0;
180 struct flagsbuf fbuf, nbuf;
181 struct ddebug_class_map *map = NULL;
182 int __outvar valid_class;
184 /* search for matching ddebugs */
185 mutex_lock(&ddebug_lock);
186 list_for_each_entry(dt, &ddebug_tables, link) {
188 /* match against the module name */
190 !match_wildcard(query->module, dt->mod_name))
193 if (query->class_string) {
194 map = ddebug_find_valid_class(dt, query->class_string, &valid_class);
198 /* constrain query, do not touch class'd callsites */
199 valid_class = _DPRINTK_CLASS_DFLT;
202 for (i = 0; i < dt->num_ddebugs; i++) {
203 struct _ddebug *dp = &dt->ddebugs[i];
205 /* match site against query-class */
206 if (dp->class_id != valid_class)
209 /* match against the source filename */
210 if (query->filename &&
211 !match_wildcard(query->filename, dp->filename) &&
212 !match_wildcard(query->filename,
213 kbasename(dp->filename)) &&
214 !match_wildcard(query->filename,
215 trim_prefix(dp->filename)))
218 /* match against the function */
219 if (query->function &&
220 !match_wildcard(query->function, dp->function))
223 /* match against the format */
225 if (*query->format == '^') {
227 /* anchored search. match must be at beginning */
228 p = strstr(dp->format, query->format+1);
231 } else if (!strstr(dp->format, query->format))
235 /* match against the line number range */
236 if (query->first_lineno &&
237 dp->lineno < query->first_lineno)
239 if (query->last_lineno &&
240 dp->lineno > query->last_lineno)
245 newflags = (dp->flags & modifiers->mask) | modifiers->flags;
246 if (newflags == dp->flags)
248 #ifdef CONFIG_JUMP_LABEL
249 if (dp->flags & _DPRINTK_FLAGS_PRINT) {
250 if (!(newflags & _DPRINTK_FLAGS_PRINT))
251 static_branch_disable(&dp->key.dd_key_true);
252 } else if (newflags & _DPRINTK_FLAGS_PRINT) {
253 static_branch_enable(&dp->key.dd_key_true);
256 v4pr_info("changed %s:%d [%s]%s %s => %s\n",
257 trim_prefix(dp->filename), dp->lineno,
258 dt->mod_name, dp->function,
259 ddebug_describe_flags(dp->flags, &fbuf),
260 ddebug_describe_flags(newflags, &nbuf));
261 dp->flags = newflags;
264 mutex_unlock(&ddebug_lock);
266 if (!nfound && verbose)
267 pr_info("no matches for query\n");
273 * Split the buffer `buf' into space-separated words.
274 * Handles simple " and ' quoting, i.e. without nested,
275 * embedded or escaped \". Return the number of words
278 static int ddebug_tokenize(char *buf, char *words[], int maxwords)
285 /* Skip leading whitespace */
286 buf = skip_spaces(buf);
288 break; /* oh, it was trailing whitespace */
290 break; /* token starts comment, skip rest of line */
292 /* find `end' of word, whitespace separated or quoted */
293 if (*buf == '"' || *buf == '\'') {
295 for (end = buf; *end && *end != quote; end++)
298 pr_err("unclosed quote: %s\n", buf);
299 return -EINVAL; /* unclosed quote */
302 for (end = buf; *end && !isspace(*end); end++)
307 /* `buf' is start of word, `end' is one past its end */
308 if (nwords == maxwords) {
309 pr_err("too many words, legal max <=%d\n", maxwords);
310 return -EINVAL; /* ran out of words[] before bytes */
313 *end++ = '\0'; /* terminate the word */
314 words[nwords++] = buf;
320 pr_info("split into words:");
321 for (i = 0; i < nwords; i++)
322 pr_cont(" \"%s\"", words[i]);
330 * Parse a single line number. Note that the empty string ""
331 * is treated as a special case and converted to zero, which
332 * is later treated as a "don't care" value.
334 static inline int parse_lineno(const char *str, unsigned int *val)
341 if (kstrtouint(str, 10, val) < 0) {
342 pr_err("bad line-number: %s\n", str);
348 static int parse_linerange(struct ddebug_query *query, const char *first)
350 char *last = strchr(first, '-');
352 if (query->first_lineno || query->last_lineno) {
353 pr_err("match-spec: line used 2x\n");
358 if (parse_lineno(first, &query->first_lineno) < 0)
361 /* range <first>-<last> */
362 if (parse_lineno(last, &query->last_lineno) < 0)
365 /* special case for last lineno not specified */
366 if (query->last_lineno == 0)
367 query->last_lineno = UINT_MAX;
369 if (query->last_lineno < query->first_lineno) {
370 pr_err("last-line:%d < 1st-line:%d\n",
372 query->first_lineno);
376 query->last_lineno = query->first_lineno;
378 v3pr_info("parsed line %d-%d\n", query->first_lineno,
383 static int check_set(const char **dest, char *src, char *name)
389 pr_err("match-spec:%s val:%s overridden by %s\n",
397 * Parse words[] as a ddebug query specification, which is a series
398 * of (keyword, value) pairs chosen from these possibilities:
400 * func <function-name>
401 * file <full-pathname>
402 * file <base-filename>
403 * module <module-name>
404 * format <escaped-string-to-find-in-format>
406 * line <first-lineno>-<last-lineno> // where either may be empty
408 * Only 1 of each type is allowed.
409 * Returns 0 on success, <0 on error.
411 static int ddebug_parse_query(char *words[], int nwords,
412 struct ddebug_query *query, const char *modname)
418 /* check we have an even number of words */
419 if (nwords % 2 != 0) {
420 pr_err("expecting pairs of match-spec <value>\n");
424 for (i = 0; i < nwords; i += 2) {
425 char *keyword = words[i];
426 char *arg = words[i+1];
428 if (!strcmp(keyword, "func")) {
429 rc = check_set(&query->function, arg, "func");
430 } else if (!strcmp(keyword, "file")) {
431 if (check_set(&query->filename, arg, "file"))
434 /* tail :$info is function or line-range */
435 fline = strchr(query->filename, ':');
439 if (isalpha(*fline) || *fline == '*' || *fline == '?') {
440 /* take as function name */
441 if (check_set(&query->function, fline, "func"))
444 if (parse_linerange(query, fline))
447 } else if (!strcmp(keyword, "module")) {
448 rc = check_set(&query->module, arg, "module");
449 } else if (!strcmp(keyword, "format")) {
450 string_unescape_inplace(arg, UNESCAPE_SPACE |
453 rc = check_set(&query->format, arg, "format");
454 } else if (!strcmp(keyword, "line")) {
455 if (parse_linerange(query, arg))
457 } else if (!strcmp(keyword, "class")) {
458 rc = check_set(&query->class_string, arg, "class");
460 pr_err("unknown keyword \"%s\"\n", keyword);
466 if (!query->module && modname)
468 * support $modname.dyndbg=<multiple queries>, when
469 * not given in the query itself
471 query->module = modname;
473 vpr_info_dq(query, "parsed");
478 * Parse `str' as a flags specification, format [-+=][p]+.
479 * Sets up *maskp and *flagsp to be used when changing the
480 * flags fields of matched _ddebug's. Returns 0 on success
483 static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
494 pr_err("bad flag-op %c, at start of %s\n", *str, str);
497 v3pr_info("op='%c'\n", op);
499 for (; *str ; ++str) {
500 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
501 if (*str == opt_array[i].opt_char) {
502 modifiers->flags |= opt_array[i].flag;
507 pr_err("unknown flag '%c'\n", *str);
511 v3pr_info("flags=0x%x\n", modifiers->flags);
513 /* calculate final flags, mask based upon op */
516 /* modifiers->flags already set */
520 modifiers->mask = ~0U;
523 modifiers->mask = ~modifiers->flags;
524 modifiers->flags = 0;
527 v3pr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
532 static int ddebug_exec_query(char *query_string, const char *modname)
534 struct flag_settings modifiers = {};
535 struct ddebug_query query = {};
538 char *words[MAXWORDS];
540 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
542 pr_err("tokenize failed\n");
545 /* check flags 1st (last arg) so query is pairs of spec,val */
546 if (ddebug_parse_flags(words[nwords-1], &modifiers)) {
547 pr_err("flags parse failed\n");
550 if (ddebug_parse_query(words, nwords-1, &query, modname)) {
551 pr_err("query parse failed\n");
554 /* actually go and implement the change */
555 nfound = ddebug_change(&query, &modifiers);
556 vpr_info_dq(&query, nfound ? "applied" : "no-match");
561 /* handle multiple queries in query string, continue on error, return
562 last error or number of matching callsites. Module name is either
563 in param (for boot arg) or perhaps in query string.
565 static int ddebug_exec_queries(char *query, const char *modname)
568 int i, errs = 0, exitcode = 0, rc, nfound = 0;
570 for (i = 0; query; query = split) {
571 split = strpbrk(query, ";\n");
575 query = skip_spaces(query);
576 if (!query || !*query || *query == '#')
579 vpr_info("query %d: \"%s\" mod:%s\n", i, query, modname ?: "*");
581 rc = ddebug_exec_query(query, modname);
591 v2pr_info("processed %d queries, with %d matches, %d errs\n",
599 #define PREFIX_SIZE 64
601 static int remaining(int wrote)
603 if (PREFIX_SIZE - wrote > 0)
604 return PREFIX_SIZE - wrote;
608 static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
613 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
615 pos += snprintf(buf + pos, remaining(pos), "<intr> ");
617 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
618 task_pid_vnr(current));
621 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
622 pos += snprintf(buf + pos, remaining(pos), "%s:",
624 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
625 pos += snprintf(buf + pos, remaining(pos), "%s:",
627 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
628 pos += snprintf(buf + pos, remaining(pos), "%d:",
630 if (pos - pos_after_tid)
631 pos += snprintf(buf + pos, remaining(pos), " ");
632 if (pos >= PREFIX_SIZE)
633 buf[PREFIX_SIZE - 1] = '\0';
638 static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)
640 if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_ANY))
641 return __dynamic_emit_prefix(desc, buf);
645 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
648 struct va_format vaf;
649 char buf[PREFIX_SIZE] = "";
659 printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
663 EXPORT_SYMBOL(__dynamic_pr_debug);
665 void __dynamic_dev_dbg(struct _ddebug *descriptor,
666 const struct device *dev, const char *fmt, ...)
668 struct va_format vaf;
680 printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
682 char buf[PREFIX_SIZE] = "";
684 dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
685 dynamic_emit_prefix(descriptor, buf),
686 dev_driver_string(dev), dev_name(dev),
692 EXPORT_SYMBOL(__dynamic_dev_dbg);
696 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
697 const struct net_device *dev, const char *fmt, ...)
699 struct va_format vaf;
710 if (dev && dev->dev.parent) {
711 char buf[PREFIX_SIZE] = "";
713 dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
715 dynamic_emit_prefix(descriptor, buf),
716 dev_driver_string(dev->dev.parent),
717 dev_name(dev->dev.parent),
718 netdev_name(dev), netdev_reg_state(dev),
721 printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
722 netdev_reg_state(dev), &vaf);
724 printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
729 EXPORT_SYMBOL(__dynamic_netdev_dbg);
733 #if IS_ENABLED(CONFIG_INFINIBAND)
735 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
736 const struct ib_device *ibdev, const char *fmt, ...)
738 struct va_format vaf;
746 if (ibdev && ibdev->dev.parent) {
747 char buf[PREFIX_SIZE] = "";
749 dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
751 dynamic_emit_prefix(descriptor, buf),
752 dev_driver_string(ibdev->dev.parent),
753 dev_name(ibdev->dev.parent),
754 dev_name(&ibdev->dev),
757 printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
759 printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
764 EXPORT_SYMBOL(__dynamic_ibdev_dbg);
769 * Install a noop handler to make dyndbg look like a normal kernel cli param.
770 * This avoids warnings about dyndbg being an unknown cli param when supplied
773 static __init int dyndbg_setup(char *str)
778 __setup("dyndbg=", dyndbg_setup);
781 * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
782 * command text from userspace, parses and executes it.
784 #define USER_BUF_PAGE 4096
785 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
786 size_t len, loff_t *offp)
793 if (len > USER_BUF_PAGE - 1) {
794 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
797 tmpbuf = memdup_user_nul(ubuf, len);
799 return PTR_ERR(tmpbuf);
800 v2pr_info("read %zu bytes from userspace\n", len);
802 ret = ddebug_exec_queries(tmpbuf, NULL);
812 * Set the iterator to point to the first _ddebug object
813 * and return a pointer to that first object. Returns
814 * NULL if there are no _ddebugs at all.
816 static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
818 if (list_empty(&ddebug_tables)) {
822 iter->table = list_entry(ddebug_tables.next,
823 struct ddebug_table, link);
824 iter->idx = iter->table->num_ddebugs;
825 return &iter->table->ddebugs[--iter->idx];
829 * Advance the iterator to point to the next _ddebug
830 * object from the one the iterator currently points at,
831 * and returns a pointer to the new _ddebug. Returns
832 * NULL if the iterator has seen all the _ddebugs.
834 static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
836 if (iter->table == NULL)
838 if (--iter->idx < 0) {
839 /* iterate to next table */
840 if (list_is_last(&iter->table->link, &ddebug_tables)) {
844 iter->table = list_entry(iter->table->link.next,
845 struct ddebug_table, link);
846 iter->idx = iter->table->num_ddebugs;
849 return &iter->table->ddebugs[iter->idx];
853 * Seq_ops start method. Called at the start of every
854 * read() call from userspace. Takes the ddebug_lock and
855 * seeks the seq_file's iterator to the given position.
857 static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
859 struct ddebug_iter *iter = m->private;
863 mutex_lock(&ddebug_lock);
866 return SEQ_START_TOKEN;
869 dp = ddebug_iter_first(iter);
870 while (dp != NULL && --n > 0)
871 dp = ddebug_iter_next(iter);
876 * Seq_ops next method. Called several times within a read()
877 * call from userspace, with ddebug_lock held. Walks to the
878 * next _ddebug object with a special case for the header line.
880 static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
882 struct ddebug_iter *iter = m->private;
885 if (p == SEQ_START_TOKEN)
886 dp = ddebug_iter_first(iter);
888 dp = ddebug_iter_next(iter);
893 #define class_in_range(class_id, map) \
894 (class_id >= map->base && class_id < map->base + map->length)
896 static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
898 struct ddebug_class_map *map;
900 list_for_each_entry(map, &iter->table->maps, link)
901 if (class_in_range(dp->class_id, map))
902 return map->class_names[dp->class_id - map->base];
908 * Seq_ops show method. Called several times within a read()
909 * call from userspace, with ddebug_lock held. Formats the
910 * current _ddebug as a single human-readable line, with a
911 * special case for the header line.
913 static int ddebug_proc_show(struct seq_file *m, void *p)
915 struct ddebug_iter *iter = m->private;
916 struct _ddebug *dp = p;
917 struct flagsbuf flags;
920 if (p == SEQ_START_TOKEN) {
922 "# filename:lineno [module]function flags format\n");
926 seq_printf(m, "%s:%u [%s]%s =%s \"",
927 trim_prefix(dp->filename), dp->lineno,
928 iter->table->mod_name, dp->function,
929 ddebug_describe_flags(dp->flags, &flags));
930 seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
933 if (dp->class_id != _DPRINTK_CLASS_DFLT) {
934 class = ddebug_class_name(iter, dp);
936 seq_printf(m, " class:%s", class);
938 seq_printf(m, " class unknown, _id:%d", dp->class_id);
946 * Seq_ops stop method. Called at the end of each read()
947 * call from userspace. Drops ddebug_lock.
949 static void ddebug_proc_stop(struct seq_file *m, void *p)
951 mutex_unlock(&ddebug_lock);
954 static const struct seq_operations ddebug_proc_seqops = {
955 .start = ddebug_proc_start,
956 .next = ddebug_proc_next,
957 .show = ddebug_proc_show,
958 .stop = ddebug_proc_stop
961 static int ddebug_proc_open(struct inode *inode, struct file *file)
963 return seq_open_private(file, &ddebug_proc_seqops,
964 sizeof(struct ddebug_iter));
967 static const struct file_operations ddebug_proc_fops = {
968 .owner = THIS_MODULE,
969 .open = ddebug_proc_open,
972 .release = seq_release_private,
973 .write = ddebug_proc_write
976 static const struct proc_ops proc_fops = {
977 .proc_open = ddebug_proc_open,
978 .proc_read = seq_read,
979 .proc_lseek = seq_lseek,
980 .proc_release = seq_release_private,
981 .proc_write = ddebug_proc_write
984 static void ddebug_attach_module_classes(struct ddebug_table *dt,
985 struct ddebug_class_map *classes,
988 struct ddebug_class_map *cm;
991 for (cm = classes, i = 0; i < num_classes; i++, cm++) {
993 if (!strcmp(cm->mod_name, dt->mod_name)) {
995 v2pr_info("class[%d]: module:%s base:%d len:%d ty:%d\n", i,
996 cm->mod_name, cm->base, cm->length, cm->map_type);
998 for (j = 0; j < cm->length; j++)
999 v3pr_info(" %d: %d %s\n", j + cm->base, j,
1000 cm->class_names[j]);
1002 list_add(&cm->link, &dt->maps);
1007 vpr_info("module:%s attached %d classes\n", dt->mod_name, ct);
1011 * Allocate a new ddebug_table for the given module
1012 * and add it to the global list.
1014 static int __ddebug_add_module(struct _ddebug_info *di, unsigned int base,
1015 const char *modname)
1017 struct ddebug_table *dt;
1019 v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
1020 if (!di->num_descs) {
1021 v3pr_info(" skip %s\n", modname);
1025 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
1027 pr_err("error adding module: %s\n", modname);
1031 * For built-in modules, name lives in .rodata and is
1032 * immortal. For loaded modules, name points at the name[]
1033 * member of struct module, which lives at least as long as
1034 * this struct ddebug_table.
1036 dt->mod_name = modname;
1037 dt->ddebugs = di->descs;
1038 dt->num_ddebugs = di->num_descs;
1040 INIT_LIST_HEAD(&dt->link);
1041 INIT_LIST_HEAD(&dt->maps);
1043 if (di->classes && di->num_classes)
1044 ddebug_attach_module_classes(dt, di->classes, di->num_classes);
1046 mutex_lock(&ddebug_lock);
1047 list_add_tail(&dt->link, &ddebug_tables);
1048 mutex_unlock(&ddebug_lock);
1050 vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
1054 int ddebug_add_module(struct _ddebug_info *di, const char *modname)
1056 return __ddebug_add_module(di, 0, modname);
1059 /* helper for ddebug_dyndbg_(boot|module)_param_cb */
1060 static int ddebug_dyndbg_param_cb(char *param, char *val,
1061 const char *modname, int on_err)
1065 sep = strchr(param, '.');
1067 /* needed only for ddebug_dyndbg_boot_param_cb */
1072 if (strcmp(param, "dyndbg"))
1073 return on_err; /* determined by caller */
1075 ddebug_exec_queries((val ? val : "+p"), modname);
1077 return 0; /* query failure shouldn't stop module load */
1080 /* handle both dyndbg and $module.dyndbg params at boot */
1081 static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
1082 const char *unused, void *arg)
1084 vpr_info("%s=\"%s\"\n", param, val);
1085 return ddebug_dyndbg_param_cb(param, val, NULL, 0);
1089 * modprobe foo finds foo.params in boot-args, strips "foo.", and
1090 * passes them to load_module(). This callback gets unknown params,
1091 * processes dyndbg params, rejects others.
1093 int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
1095 vpr_info("module: %s %s=\"%s\"\n", module, param, val);
1096 return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
1099 static void ddebug_table_free(struct ddebug_table *dt)
1101 list_del_init(&dt->link);
1106 * Called in response to a module being unloaded. Removes
1107 * any ddebug_table's which point at the module.
1109 int ddebug_remove_module(const char *mod_name)
1111 struct ddebug_table *dt, *nextdt;
1114 mutex_lock(&ddebug_lock);
1115 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
1116 if (dt->mod_name == mod_name) {
1117 ddebug_table_free(dt);
1122 mutex_unlock(&ddebug_lock);
1124 v2pr_info("removed module \"%s\"\n", mod_name);
1128 static void ddebug_remove_all_tables(void)
1130 mutex_lock(&ddebug_lock);
1131 while (!list_empty(&ddebug_tables)) {
1132 struct ddebug_table *dt = list_entry(ddebug_tables.next,
1133 struct ddebug_table,
1135 ddebug_table_free(dt);
1137 mutex_unlock(&ddebug_lock);
1140 static __initdata int ddebug_init_success;
1142 static int __init dynamic_debug_init_control(void)
1144 struct proc_dir_entry *procfs_dir;
1145 struct dentry *debugfs_dir;
1147 if (!ddebug_init_success)
1150 /* Create the control file in debugfs if it is enabled */
1151 if (debugfs_initialized()) {
1152 debugfs_dir = debugfs_create_dir("dynamic_debug", NULL);
1153 debugfs_create_file("control", 0644, debugfs_dir, NULL,
1157 /* Also create the control file in procfs */
1158 procfs_dir = proc_mkdir("dynamic_debug", NULL);
1160 proc_create("control", 0644, procfs_dir, &proc_fops);
1165 static int __init dynamic_debug_init(void)
1167 struct _ddebug *iter, *iter_mod_start;
1168 int ret, i, mod_sites, mod_ct;
1169 const char *modname;
1172 struct _ddebug_info di = {
1173 .descs = __start___dyndbg,
1174 .classes = __start___dyndbg_classes,
1175 .num_descs = __stop___dyndbg - __start___dyndbg,
1176 .num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
1179 if (&__start___dyndbg == &__stop___dyndbg) {
1180 if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
1181 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1184 pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
1185 ddebug_init_success = 1;
1189 iter = iter_mod_start = __start___dyndbg;
1190 modname = iter->modname;
1191 i = mod_sites = mod_ct = 0;
1193 for (; iter < __stop___dyndbg; iter++, i++, mod_sites++) {
1195 if (strcmp(modname, iter->modname)) {
1197 di.num_descs = mod_sites;
1198 di.descs = iter_mod_start;
1199 ret = __ddebug_add_module(&di, i - mod_sites, modname);
1204 modname = iter->modname;
1205 iter_mod_start = iter;
1208 di.num_descs = mod_sites;
1209 di.descs = iter_mod_start;
1210 ret = __ddebug_add_module(&di, i - mod_sites, modname);
1214 ddebug_init_success = 1;
1215 vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg section\n",
1216 i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
1217 (int)((i * sizeof(struct _ddebug)) >> 10));
1220 v2pr_info(" %d builtin ddebug class-maps\n", di.num_classes);
1222 /* now that ddebug tables are loaded, process all boot args
1223 * again to find and activate queries given in dyndbg params.
1224 * While this has already been done for known boot params, it
1225 * ignored the unknown ones (dyndbg in particular). Reusing
1226 * parse_args avoids ad-hoc parsing. This will also attempt
1227 * to activate queries for not-yet-loaded modules, which is
1228 * slightly noisy if verbose, but harmless.
1230 cmdline = kstrdup(saved_command_line, GFP_KERNEL);
1231 parse_args("dyndbg params", cmdline, NULL,
1232 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
1237 ddebug_remove_all_tables();
1240 /* Allow early initialization for boot messages via boot param */
1241 early_initcall(dynamic_debug_init);
1243 /* Debugfs setup must be done later */
1244 fs_initcall(dynamic_debug_init_control);