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[];
46 struct list_head link;
48 unsigned int num_ddebugs;
49 struct _ddebug *ddebugs;
57 unsigned int first_lineno, last_lineno;
61 struct ddebug_table *table;
65 struct flag_settings {
70 static DEFINE_MUTEX(ddebug_lock);
71 static LIST_HEAD(ddebug_tables);
73 module_param(verbose, int, 0644);
75 /* Return the path relative to source root */
76 static inline const char *trim_prefix(const char *path)
78 int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
80 if (strncmp(path, __FILE__, skip))
81 skip = 0; /* prefix mismatch, don't skip */
86 static 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, '_' },
95 struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; };
97 /* format a string into buf[] which describes the _ddebug's flags */
98 static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb)
103 for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
104 if (flags & opt_array[i].flag)
105 *p++ = opt_array[i].opt_char;
113 #define vnpr_info(lvl, fmt, ...) \
115 if (verbose >= lvl) \
116 pr_info(fmt, ##__VA_ARGS__); \
119 #define vpr_info(fmt, ...) vnpr_info(1, fmt, ##__VA_ARGS__)
120 #define v2pr_info(fmt, ...) vnpr_info(2, fmt, ##__VA_ARGS__)
122 static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
124 /* trim any trailing newlines */
128 fmtlen = strlen(query->format);
129 while (fmtlen && query->format[fmtlen - 1] == '\n')
133 vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n",
135 query->function ?: "",
136 query->filename ?: "",
138 fmtlen, query->format ?: "",
139 query->first_lineno, query->last_lineno);
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.
148 static int ddebug_change(const struct ddebug_query *query,
149 struct flag_settings *modifiers)
152 struct ddebug_table *dt;
153 unsigned int newflags;
154 unsigned int nfound = 0;
155 struct flagsbuf fbuf;
157 /* search for matching ddebugs */
158 mutex_lock(&ddebug_lock);
159 list_for_each_entry(dt, &ddebug_tables, link) {
161 /* match against the module name */
163 !match_wildcard(query->module, dt->mod_name))
166 for (i = 0; i < dt->num_ddebugs; i++) {
167 struct _ddebug *dp = &dt->ddebugs[i];
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)))
178 /* match against the function */
179 if (query->function &&
180 !match_wildcard(query->function, dp->function))
183 /* match against the format */
185 if (*query->format == '^') {
187 /* anchored search. match must be at beginning */
188 p = strstr(dp->format, query->format+1);
191 } else if (!strstr(dp->format, query->format))
195 /* match against the line number range */
196 if (query->first_lineno &&
197 dp->lineno < query->first_lineno)
199 if (query->last_lineno &&
200 dp->lineno > query->last_lineno)
205 newflags = (dp->flags & modifiers->mask) | modifiers->flags;
206 if (newflags == dp->flags)
208 #ifdef CONFIG_JUMP_LABEL
209 if (dp->flags & _DPRINTK_FLAGS_PRINT) {
210 if (!(newflags & _DPRINTK_FLAGS_PRINT))
211 static_branch_disable(&dp->key.dd_key_true);
212 } else if (newflags & _DPRINTK_FLAGS_PRINT) {
213 static_branch_enable(&dp->key.dd_key_true);
216 dp->flags = newflags;
217 v2pr_info("changed %s:%d [%s]%s =%s\n",
218 trim_prefix(dp->filename), dp->lineno,
219 dt->mod_name, dp->function,
220 ddebug_describe_flags(dp->flags, &fbuf));
223 mutex_unlock(&ddebug_lock);
225 if (!nfound && verbose)
226 pr_info("no matches for query\n");
232 * Split the buffer `buf' into space-separated words.
233 * Handles simple " and ' quoting, i.e. without nested,
234 * embedded or escaped \". Return the number of words
237 static int ddebug_tokenize(char *buf, char *words[], int maxwords)
244 /* Skip leading whitespace */
245 buf = skip_spaces(buf);
247 break; /* oh, it was trailing whitespace */
249 break; /* token starts comment, skip rest of line */
251 /* find `end' of word, whitespace separated or quoted */
252 if (*buf == '"' || *buf == '\'') {
254 for (end = buf; *end && *end != quote; end++)
257 pr_err("unclosed quote: %s\n", buf);
258 return -EINVAL; /* unclosed quote */
261 for (end = buf; *end && !isspace(*end); end++)
264 pr_err("parse err after word:%d=%s\n", nwords,
265 nwords ? words[nwords - 1] : "<none>");
270 /* `buf' is start of word, `end' is one past its end */
271 if (nwords == maxwords) {
272 pr_err("too many words, legal max <=%d\n", maxwords);
273 return -EINVAL; /* ran out of words[] before bytes */
276 *end++ = '\0'; /* terminate the word */
277 words[nwords++] = buf;
283 pr_info("split into words:");
284 for (i = 0; i < nwords; i++)
285 pr_cont(" \"%s\"", words[i]);
293 * Parse a single line number. Note that the empty string ""
294 * is treated as a special case and converted to zero, which
295 * is later treated as a "don't care" value.
297 static inline int parse_lineno(const char *str, unsigned int *val)
304 if (kstrtouint(str, 10, val) < 0) {
305 pr_err("bad line-number: %s\n", str);
311 static int parse_linerange(struct ddebug_query *query, const char *first)
313 char *last = strchr(first, '-');
315 if (query->first_lineno || query->last_lineno) {
316 pr_err("match-spec: line used 2x\n");
321 if (parse_lineno(first, &query->first_lineno) < 0)
324 /* range <first>-<last> */
325 if (parse_lineno(last, &query->last_lineno) < 0)
328 /* special case for last lineno not specified */
329 if (query->last_lineno == 0)
330 query->last_lineno = UINT_MAX;
332 if (query->last_lineno < query->first_lineno) {
333 pr_err("last-line:%d < 1st-line:%d\n",
335 query->first_lineno);
339 query->last_lineno = query->first_lineno;
341 vpr_info("parsed line %d-%d\n", query->first_lineno,
346 static int check_set(const char **dest, char *src, char *name)
352 pr_err("match-spec:%s val:%s overridden by %s\n",
360 * Parse words[] as a ddebug query specification, which is a series
361 * of (keyword, value) pairs chosen from these possibilities:
363 * func <function-name>
364 * file <full-pathname>
365 * file <base-filename>
366 * module <module-name>
367 * format <escaped-string-to-find-in-format>
369 * line <first-lineno>-<last-lineno> // where either may be empty
371 * Only 1 of each type is allowed.
372 * Returns 0 on success, <0 on error.
374 static int ddebug_parse_query(char *words[], int nwords,
375 struct ddebug_query *query, const char *modname)
381 /* check we have an even number of words */
382 if (nwords % 2 != 0) {
383 pr_err("expecting pairs of match-spec <value>\n");
387 for (i = 0; i < nwords; i += 2) {
388 char *keyword = words[i];
389 char *arg = words[i+1];
391 if (!strcmp(keyword, "func")) {
392 rc = check_set(&query->function, arg, "func");
393 } else if (!strcmp(keyword, "file")) {
394 if (check_set(&query->filename, arg, "file"))
397 /* tail :$info is function or line-range */
398 fline = strchr(query->filename, ':');
402 if (isalpha(*fline) || *fline == '*' || *fline == '?') {
403 /* take as function name */
404 if (check_set(&query->function, fline, "func"))
407 if (parse_linerange(query, fline))
410 } else if (!strcmp(keyword, "module")) {
411 rc = check_set(&query->module, arg, "module");
412 } else if (!strcmp(keyword, "format")) {
413 string_unescape_inplace(arg, UNESCAPE_SPACE |
416 rc = check_set(&query->format, arg, "format");
417 } else if (!strcmp(keyword, "line")) {
418 if (parse_linerange(query, arg))
421 pr_err("unknown keyword \"%s\"\n", keyword);
427 if (!query->module && modname)
429 * support $modname.dyndbg=<multiple queries>, when
430 * not given in the query itself
432 query->module = modname;
434 vpr_info_dq(query, "parsed");
439 * Parse `str' as a flags specification, format [-+=][p]+.
440 * Sets up *maskp and *flagsp to be used when changing the
441 * flags fields of matched _ddebug's. Returns 0 on success
444 static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
455 pr_err("bad flag-op %c, at start of %s\n", *str, str);
458 vpr_info("op='%c'\n", op);
460 for (; *str ; ++str) {
461 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
462 if (*str == opt_array[i].opt_char) {
463 modifiers->flags |= opt_array[i].flag;
468 pr_err("unknown flag '%c'\n", *str);
472 vpr_info("flags=0x%x\n", modifiers->flags);
474 /* calculate final flags, mask based upon op */
477 /* modifiers->flags already set */
481 modifiers->mask = ~0U;
484 modifiers->mask = ~modifiers->flags;
485 modifiers->flags = 0;
488 vpr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
493 static int ddebug_exec_query(char *query_string, const char *modname)
495 struct flag_settings modifiers = {};
496 struct ddebug_query query = {};
499 char *words[MAXWORDS];
501 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
503 pr_err("tokenize failed\n");
506 /* check flags 1st (last arg) so query is pairs of spec,val */
507 if (ddebug_parse_flags(words[nwords-1], &modifiers)) {
508 pr_err("flags parse failed\n");
511 if (ddebug_parse_query(words, nwords-1, &query, modname)) {
512 pr_err("query parse failed\n");
515 /* actually go and implement the change */
516 nfound = ddebug_change(&query, &modifiers);
517 vpr_info_dq(&query, nfound ? "applied" : "no-match");
522 /* handle multiple queries in query string, continue on error, return
523 last error or number of matching callsites. Module name is either
524 in param (for boot arg) or perhaps in query string.
526 static int ddebug_exec_queries(char *query, const char *modname)
529 int i, errs = 0, exitcode = 0, rc, nfound = 0;
531 for (i = 0; query; query = split) {
532 split = strpbrk(query, ";\n");
536 query = skip_spaces(query);
537 if (!query || !*query || *query == '#')
540 vpr_info("query %d: \"%s\"\n", i, query);
542 rc = ddebug_exec_query(query, modname);
551 vpr_info("processed %d queries, with %d matches, %d errs\n",
559 #define PREFIX_SIZE 64
561 static int remaining(int wrote)
563 if (PREFIX_SIZE - wrote > 0)
564 return PREFIX_SIZE - wrote;
568 static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
575 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
577 pos += snprintf(buf + pos, remaining(pos), "<intr> ");
579 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
580 task_pid_vnr(current));
583 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
584 pos += snprintf(buf + pos, remaining(pos), "%s:",
586 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
587 pos += snprintf(buf + pos, remaining(pos), "%s:",
589 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
590 pos += snprintf(buf + pos, remaining(pos), "%d:",
592 if (pos - pos_after_tid)
593 pos += snprintf(buf + pos, remaining(pos), " ");
594 if (pos >= PREFIX_SIZE)
595 buf[PREFIX_SIZE - 1] = '\0';
600 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
603 struct va_format vaf;
604 char buf[PREFIX_SIZE];
614 printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
618 EXPORT_SYMBOL(__dynamic_pr_debug);
620 void __dynamic_dev_dbg(struct _ddebug *descriptor,
621 const struct device *dev, const char *fmt, ...)
623 struct va_format vaf;
635 printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
637 char buf[PREFIX_SIZE];
639 dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
640 dynamic_emit_prefix(descriptor, buf),
641 dev_driver_string(dev), dev_name(dev),
647 EXPORT_SYMBOL(__dynamic_dev_dbg);
651 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
652 const struct net_device *dev, const char *fmt, ...)
654 struct va_format vaf;
665 if (dev && dev->dev.parent) {
666 char buf[PREFIX_SIZE];
668 dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
670 dynamic_emit_prefix(descriptor, buf),
671 dev_driver_string(dev->dev.parent),
672 dev_name(dev->dev.parent),
673 netdev_name(dev), netdev_reg_state(dev),
676 printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
677 netdev_reg_state(dev), &vaf);
679 printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
684 EXPORT_SYMBOL(__dynamic_netdev_dbg);
688 #if IS_ENABLED(CONFIG_INFINIBAND)
690 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
691 const struct ib_device *ibdev, const char *fmt, ...)
693 struct va_format vaf;
701 if (ibdev && ibdev->dev.parent) {
702 char buf[PREFIX_SIZE];
704 dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
706 dynamic_emit_prefix(descriptor, buf),
707 dev_driver_string(ibdev->dev.parent),
708 dev_name(ibdev->dev.parent),
709 dev_name(&ibdev->dev),
712 printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
714 printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
719 EXPORT_SYMBOL(__dynamic_ibdev_dbg);
723 #define DDEBUG_STRING_SIZE 1024
724 static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
726 static __init int ddebug_setup_query(char *str)
728 if (strlen(str) >= DDEBUG_STRING_SIZE) {
729 pr_warn("ddebug boot param string too large\n");
732 strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
736 __setup("ddebug_query=", ddebug_setup_query);
739 * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
740 * command text from userspace, parses and executes it.
742 #define USER_BUF_PAGE 4096
743 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
744 size_t len, loff_t *offp)
751 if (len > USER_BUF_PAGE - 1) {
752 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
755 tmpbuf = memdup_user_nul(ubuf, len);
757 return PTR_ERR(tmpbuf);
758 vpr_info("read %d bytes from userspace\n", (int)len);
760 ret = ddebug_exec_queries(tmpbuf, NULL);
770 * Set the iterator to point to the first _ddebug object
771 * and return a pointer to that first object. Returns
772 * NULL if there are no _ddebugs at all.
774 static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
776 if (list_empty(&ddebug_tables)) {
781 iter->table = list_entry(ddebug_tables.next,
782 struct ddebug_table, link);
784 return &iter->table->ddebugs[iter->idx];
788 * Advance the iterator to point to the next _ddebug
789 * object from the one the iterator currently points at,
790 * and returns a pointer to the new _ddebug. Returns
791 * NULL if the iterator has seen all the _ddebugs.
793 static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
795 if (iter->table == NULL)
797 if (++iter->idx == iter->table->num_ddebugs) {
798 /* iterate to next table */
800 if (list_is_last(&iter->table->link, &ddebug_tables)) {
804 iter->table = list_entry(iter->table->link.next,
805 struct ddebug_table, link);
807 return &iter->table->ddebugs[iter->idx];
811 * Seq_ops start method. Called at the start of every
812 * read() call from userspace. Takes the ddebug_lock and
813 * seeks the seq_file's iterator to the given position.
815 static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
817 struct ddebug_iter *iter = m->private;
821 mutex_lock(&ddebug_lock);
824 return SEQ_START_TOKEN;
827 dp = ddebug_iter_first(iter);
828 while (dp != NULL && --n > 0)
829 dp = ddebug_iter_next(iter);
834 * Seq_ops next method. Called several times within a read()
835 * call from userspace, with ddebug_lock held. Walks to the
836 * next _ddebug object with a special case for the header line.
838 static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
840 struct ddebug_iter *iter = m->private;
843 if (p == SEQ_START_TOKEN)
844 dp = ddebug_iter_first(iter);
846 dp = ddebug_iter_next(iter);
852 * Seq_ops show method. Called several times within a read()
853 * call from userspace, with ddebug_lock held. Formats the
854 * current _ddebug as a single human-readable line, with a
855 * special case for the header line.
857 static int ddebug_proc_show(struct seq_file *m, void *p)
859 struct ddebug_iter *iter = m->private;
860 struct _ddebug *dp = p;
861 struct flagsbuf flags;
863 if (p == SEQ_START_TOKEN) {
865 "# filename:lineno [module]function flags format\n");
869 seq_printf(m, "%s:%u [%s]%s =%s \"",
870 trim_prefix(dp->filename), dp->lineno,
871 iter->table->mod_name, dp->function,
872 ddebug_describe_flags(dp->flags, &flags));
873 seq_escape(m, dp->format, "\t\r\n\"");
880 * Seq_ops stop method. Called at the end of each read()
881 * call from userspace. Drops ddebug_lock.
883 static void ddebug_proc_stop(struct seq_file *m, void *p)
885 mutex_unlock(&ddebug_lock);
888 static const struct seq_operations ddebug_proc_seqops = {
889 .start = ddebug_proc_start,
890 .next = ddebug_proc_next,
891 .show = ddebug_proc_show,
892 .stop = ddebug_proc_stop
895 static int ddebug_proc_open(struct inode *inode, struct file *file)
897 vpr_info("called\n");
898 return seq_open_private(file, &ddebug_proc_seqops,
899 sizeof(struct ddebug_iter));
902 static const struct file_operations ddebug_proc_fops = {
903 .owner = THIS_MODULE,
904 .open = ddebug_proc_open,
907 .release = seq_release_private,
908 .write = ddebug_proc_write
911 static const struct proc_ops proc_fops = {
912 .proc_open = ddebug_proc_open,
913 .proc_read = seq_read,
914 .proc_lseek = seq_lseek,
915 .proc_release = seq_release_private,
916 .proc_write = ddebug_proc_write
920 * Allocate a new ddebug_table for the given module
921 * and add it to the global list.
923 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
926 struct ddebug_table *dt;
928 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
930 pr_err("error adding module: %s\n", name);
934 * For built-in modules, name lives in .rodata and is
935 * immortal. For loaded modules, name points at the name[]
936 * member of struct module, which lives at least as long as
937 * this struct ddebug_table.
943 mutex_lock(&ddebug_lock);
944 list_add(&dt->link, &ddebug_tables);
945 mutex_unlock(&ddebug_lock);
947 v2pr_info("%3u debug prints in module %s\n", n, dt->mod_name);
951 /* helper for ddebug_dyndbg_(boot|module)_param_cb */
952 static int ddebug_dyndbg_param_cb(char *param, char *val,
953 const char *modname, int on_err)
957 sep = strchr(param, '.');
959 /* needed only for ddebug_dyndbg_boot_param_cb */
964 if (strcmp(param, "dyndbg"))
965 return on_err; /* determined by caller */
967 ddebug_exec_queries((val ? val : "+p"), modname);
969 return 0; /* query failure shouldnt stop module load */
972 /* handle both dyndbg and $module.dyndbg params at boot */
973 static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
974 const char *unused, void *arg)
976 vpr_info("%s=\"%s\"\n", param, val);
977 return ddebug_dyndbg_param_cb(param, val, NULL, 0);
981 * modprobe foo finds foo.params in boot-args, strips "foo.", and
982 * passes them to load_module(). This callback gets unknown params,
983 * processes dyndbg params, rejects others.
985 int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
987 vpr_info("module: %s %s=\"%s\"\n", module, param, val);
988 return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
991 static void ddebug_table_free(struct ddebug_table *dt)
993 list_del_init(&dt->link);
998 * Called in response to a module being unloaded. Removes
999 * any ddebug_table's which point at the module.
1001 int ddebug_remove_module(const char *mod_name)
1003 struct ddebug_table *dt, *nextdt;
1006 v2pr_info("removing module \"%s\"\n", mod_name);
1008 mutex_lock(&ddebug_lock);
1009 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
1010 if (dt->mod_name == mod_name) {
1011 ddebug_table_free(dt);
1016 mutex_unlock(&ddebug_lock);
1020 static void ddebug_remove_all_tables(void)
1022 mutex_lock(&ddebug_lock);
1023 while (!list_empty(&ddebug_tables)) {
1024 struct ddebug_table *dt = list_entry(ddebug_tables.next,
1025 struct ddebug_table,
1027 ddebug_table_free(dt);
1029 mutex_unlock(&ddebug_lock);
1032 static __initdata int ddebug_init_success;
1034 static int __init dynamic_debug_init_control(void)
1036 struct proc_dir_entry *procfs_dir;
1037 struct dentry *debugfs_dir;
1039 if (!ddebug_init_success)
1042 /* Create the control file in debugfs if it is enabled */
1043 if (debugfs_initialized()) {
1044 debugfs_dir = debugfs_create_dir("dynamic_debug", NULL);
1045 debugfs_create_file("control", 0644, debugfs_dir, NULL,
1049 /* Also create the control file in procfs */
1050 procfs_dir = proc_mkdir("dynamic_debug", NULL);
1052 proc_create("control", 0644, procfs_dir, &proc_fops);
1057 static int __init dynamic_debug_init(void)
1059 struct _ddebug *iter, *iter_start;
1060 const char *modname = NULL;
1063 int n = 0, entries = 0, modct = 0;
1065 if (&__start___dyndbg == &__stop___dyndbg) {
1066 if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
1067 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1070 pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
1071 ddebug_init_success = 1;
1074 iter = __start___dyndbg;
1075 modname = iter->modname;
1077 for (; iter < __stop___dyndbg; iter++) {
1079 if (strcmp(modname, iter->modname)) {
1081 ret = ddebug_add_module(iter_start, n, modname);
1085 modname = iter->modname;
1090 ret = ddebug_add_module(iter_start, n, modname);
1094 ddebug_init_success = 1;
1095 vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in __dyndbg section\n",
1096 modct, entries, (int)(modct * sizeof(struct ddebug_table)),
1097 (int)(entries * sizeof(struct _ddebug)));
1099 /* apply ddebug_query boot param, dont unload tables on err */
1100 if (ddebug_setup_string[0] != '\0') {
1101 pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n");
1102 ret = ddebug_exec_queries(ddebug_setup_string, NULL);
1104 pr_warn("Invalid ddebug boot param %s\n",
1105 ddebug_setup_string);
1107 pr_info("%d changes by ddebug_query\n", ret);
1109 /* now that ddebug tables are loaded, process all boot args
1110 * again to find and activate queries given in dyndbg params.
1111 * While this has already been done for known boot params, it
1112 * ignored the unknown ones (dyndbg in particular). Reusing
1113 * parse_args avoids ad-hoc parsing. This will also attempt
1114 * to activate queries for not-yet-loaded modules, which is
1115 * slightly noisy if verbose, but harmless.
1117 cmdline = kstrdup(saved_command_line, GFP_KERNEL);
1118 parse_args("dyndbg params", cmdline, NULL,
1119 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
1124 ddebug_remove_all_tables();
1127 /* Allow early initialization for boot messages via boot param */
1128 early_initcall(dynamic_debug_init);
1130 /* Debugfs setup must be done later */
1131 fs_initcall(dynamic_debug_init_control);