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 (!(modifiers->flags & _DPRINTK_FLAGS_PRINT))
211 static_branch_disable(&dp->key.dd_key_true);
212 } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT)
213 static_branch_enable(&dp->key.dd_key_true);
215 dp->flags = newflags;
216 v2pr_info("changed %s:%d [%s]%s =%s\n",
217 trim_prefix(dp->filename), dp->lineno,
218 dt->mod_name, dp->function,
219 ddebug_describe_flags(dp->flags, &fbuf));
222 mutex_unlock(&ddebug_lock);
224 if (!nfound && verbose)
225 pr_info("no matches for query\n");
231 * Split the buffer `buf' into space-separated words.
232 * Handles simple " and ' quoting, i.e. without nested,
233 * embedded or escaped \". Return the number of words
236 static int ddebug_tokenize(char *buf, char *words[], int maxwords)
243 /* Skip leading whitespace */
244 buf = skip_spaces(buf);
246 break; /* oh, it was trailing whitespace */
248 break; /* token starts comment, skip rest of line */
250 /* find `end' of word, whitespace separated or quoted */
251 if (*buf == '"' || *buf == '\'') {
253 for (end = buf; *end && *end != quote; end++)
256 pr_err("unclosed quote: %s\n", buf);
257 return -EINVAL; /* unclosed quote */
260 for (end = buf; *end && !isspace(*end); end++)
265 /* `buf' is start of word, `end' is one past its end */
266 if (nwords == maxwords) {
267 pr_err("too many words, legal max <=%d\n", maxwords);
268 return -EINVAL; /* ran out of words[] before bytes */
271 *end++ = '\0'; /* terminate the word */
272 words[nwords++] = buf;
278 pr_info("split into words:");
279 for (i = 0; i < nwords; i++)
280 pr_cont(" \"%s\"", words[i]);
288 * Parse a single line number. Note that the empty string ""
289 * is treated as a special case and converted to zero, which
290 * is later treated as a "don't care" value.
292 static inline int parse_lineno(const char *str, unsigned int *val)
299 if (kstrtouint(str, 10, val) < 0) {
300 pr_err("bad line-number: %s\n", str);
306 static int parse_linerange(struct ddebug_query *query, const char *first)
308 char *last = strchr(first, '-');
310 if (query->first_lineno || query->last_lineno) {
311 pr_err("match-spec: line used 2x\n");
316 if (parse_lineno(first, &query->first_lineno) < 0)
319 /* range <first>-<last> */
320 if (parse_lineno(last, &query->last_lineno) < 0)
323 /* special case for last lineno not specified */
324 if (query->last_lineno == 0)
325 query->last_lineno = UINT_MAX;
327 if (query->last_lineno < query->first_lineno) {
328 pr_err("last-line:%d < 1st-line:%d\n",
330 query->first_lineno);
334 query->last_lineno = query->first_lineno;
336 vpr_info("parsed line %d-%d\n", query->first_lineno,
341 static int check_set(const char **dest, char *src, char *name)
347 pr_err("match-spec:%s val:%s overridden by %s\n",
355 * Parse words[] as a ddebug query specification, which is a series
356 * of (keyword, value) pairs chosen from these possibilities:
358 * func <function-name>
359 * file <full-pathname>
360 * file <base-filename>
361 * module <module-name>
362 * format <escaped-string-to-find-in-format>
364 * line <first-lineno>-<last-lineno> // where either may be empty
366 * Only 1 of each type is allowed.
367 * Returns 0 on success, <0 on error.
369 static int ddebug_parse_query(char *words[], int nwords,
370 struct ddebug_query *query, const char *modname)
376 /* check we have an even number of words */
377 if (nwords % 2 != 0) {
378 pr_err("expecting pairs of match-spec <value>\n");
383 /* support $modname.dyndbg=<multiple queries> */
384 query->module = modname;
386 for (i = 0; i < nwords; i += 2) {
387 char *keyword = words[i];
388 char *arg = words[i+1];
390 if (!strcmp(keyword, "func")) {
391 rc = check_set(&query->function, arg, "func");
392 } else if (!strcmp(keyword, "file")) {
393 if (check_set(&query->filename, arg, "file"))
396 /* tail :$info is function or line-range */
397 fline = strchr(query->filename, ':');
401 if (isalpha(*fline) || *fline == '*' || *fline == '?') {
402 /* take as function name */
403 if (check_set(&query->function, fline, "func"))
406 if (parse_linerange(query, fline))
409 } else if (!strcmp(keyword, "module")) {
410 rc = check_set(&query->module, arg, "module");
411 } else if (!strcmp(keyword, "format")) {
412 string_unescape_inplace(arg, UNESCAPE_SPACE |
415 rc = check_set(&query->format, arg, "format");
416 } else if (!strcmp(keyword, "line")) {
417 if (parse_linerange(query, arg))
420 pr_err("unknown keyword \"%s\"\n", keyword);
426 vpr_info_dq(query, "parsed");
431 * Parse `str' as a flags specification, format [-+=][p]+.
432 * Sets up *maskp and *flagsp to be used when changing the
433 * flags fields of matched _ddebug's. Returns 0 on success
436 static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
447 pr_err("bad flag-op %c, at start of %s\n", *str, str);
450 vpr_info("op='%c'\n", op);
452 for (; *str ; ++str) {
453 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
454 if (*str == opt_array[i].opt_char) {
455 modifiers->flags |= opt_array[i].flag;
460 pr_err("unknown flag '%c'\n", *str);
464 vpr_info("flags=0x%x\n", modifiers->flags);
466 /* calculate final flags, mask based upon op */
469 /* modifiers->flags already set */
473 modifiers->mask = ~0U;
476 modifiers->mask = ~modifiers->flags;
477 modifiers->flags = 0;
480 vpr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
485 static int ddebug_exec_query(char *query_string, const char *modname)
487 struct flag_settings modifiers = {};
488 struct ddebug_query query = {};
491 char *words[MAXWORDS];
493 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
495 pr_err("tokenize failed\n");
498 /* check flags 1st (last arg) so query is pairs of spec,val */
499 if (ddebug_parse_flags(words[nwords-1], &modifiers)) {
500 pr_err("flags parse failed\n");
503 if (ddebug_parse_query(words, nwords-1, &query, modname)) {
504 pr_err("query parse failed\n");
507 /* actually go and implement the change */
508 nfound = ddebug_change(&query, &modifiers);
509 vpr_info_dq(&query, nfound ? "applied" : "no-match");
514 /* handle multiple queries in query string, continue on error, return
515 last error or number of matching callsites. Module name is either
516 in param (for boot arg) or perhaps in query string.
518 static int ddebug_exec_queries(char *query, const char *modname)
521 int i, errs = 0, exitcode = 0, rc, nfound = 0;
523 for (i = 0; query; query = split) {
524 split = strpbrk(query, ";\n");
528 query = skip_spaces(query);
529 if (!query || !*query || *query == '#')
532 vpr_info("query %d: \"%s\"\n", i, query);
534 rc = ddebug_exec_query(query, modname);
543 vpr_info("processed %d queries, with %d matches, %d errs\n",
552 * dynamic_debug_exec_queries - select and change dynamic-debug prints
553 * @query: query-string described in admin-guide/dynamic-debug-howto
554 * @modname: string containing module name, usually &module.mod_name
556 * This uses the >/proc/dynamic_debug/control reader, allowing module
557 * authors to modify their dynamic-debug callsites. The modname is
558 * canonically struct module.mod_name, but can also be null or a
559 * module-wildcard, for example: "drm*".
561 int dynamic_debug_exec_queries(const char *query, const char *modname)
564 char *qry; /* writable copy of query */
567 pr_err("non-null query/command string expected\n");
570 qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL);
574 rc = ddebug_exec_queries(qry, modname);
578 EXPORT_SYMBOL_GPL(dynamic_debug_exec_queries);
580 #define PREFIX_SIZE 64
582 static int remaining(int wrote)
584 if (PREFIX_SIZE - wrote > 0)
585 return PREFIX_SIZE - wrote;
589 static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
596 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
598 pos += snprintf(buf + pos, remaining(pos), "<intr> ");
600 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
601 task_pid_vnr(current));
604 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
605 pos += snprintf(buf + pos, remaining(pos), "%s:",
607 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
608 pos += snprintf(buf + pos, remaining(pos), "%s:",
610 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
611 pos += snprintf(buf + pos, remaining(pos), "%d:",
613 if (pos - pos_after_tid)
614 pos += snprintf(buf + pos, remaining(pos), " ");
615 if (pos >= PREFIX_SIZE)
616 buf[PREFIX_SIZE - 1] = '\0';
621 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
624 struct va_format vaf;
625 char buf[PREFIX_SIZE];
635 printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
639 EXPORT_SYMBOL(__dynamic_pr_debug);
641 void __dynamic_dev_dbg(struct _ddebug *descriptor,
642 const struct device *dev, const char *fmt, ...)
644 struct va_format vaf;
656 printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
658 char buf[PREFIX_SIZE];
660 dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
661 dynamic_emit_prefix(descriptor, buf),
662 dev_driver_string(dev), dev_name(dev),
668 EXPORT_SYMBOL(__dynamic_dev_dbg);
672 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
673 const struct net_device *dev, const char *fmt, ...)
675 struct va_format vaf;
686 if (dev && dev->dev.parent) {
687 char buf[PREFIX_SIZE];
689 dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
691 dynamic_emit_prefix(descriptor, buf),
692 dev_driver_string(dev->dev.parent),
693 dev_name(dev->dev.parent),
694 netdev_name(dev), netdev_reg_state(dev),
697 printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
698 netdev_reg_state(dev), &vaf);
700 printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
705 EXPORT_SYMBOL(__dynamic_netdev_dbg);
709 #if IS_ENABLED(CONFIG_INFINIBAND)
711 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
712 const struct ib_device *ibdev, const char *fmt, ...)
714 struct va_format vaf;
722 if (ibdev && ibdev->dev.parent) {
723 char buf[PREFIX_SIZE];
725 dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
727 dynamic_emit_prefix(descriptor, buf),
728 dev_driver_string(ibdev->dev.parent),
729 dev_name(ibdev->dev.parent),
730 dev_name(&ibdev->dev),
733 printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
735 printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
740 EXPORT_SYMBOL(__dynamic_ibdev_dbg);
744 #define DDEBUG_STRING_SIZE 1024
745 static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
747 static __init int ddebug_setup_query(char *str)
749 if (strlen(str) >= DDEBUG_STRING_SIZE) {
750 pr_warn("ddebug boot param string too large\n");
753 strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
757 __setup("ddebug_query=", ddebug_setup_query);
760 * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
761 * command text from userspace, parses and executes it.
763 #define USER_BUF_PAGE 4096
764 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
765 size_t len, loff_t *offp)
772 if (len > USER_BUF_PAGE - 1) {
773 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
776 tmpbuf = memdup_user_nul(ubuf, len);
778 return PTR_ERR(tmpbuf);
779 vpr_info("read %d bytes from userspace\n", (int)len);
781 ret = ddebug_exec_queries(tmpbuf, NULL);
791 * Set the iterator to point to the first _ddebug object
792 * and return a pointer to that first object. Returns
793 * NULL if there are no _ddebugs at all.
795 static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
797 if (list_empty(&ddebug_tables)) {
802 iter->table = list_entry(ddebug_tables.next,
803 struct ddebug_table, link);
805 return &iter->table->ddebugs[iter->idx];
809 * Advance the iterator to point to the next _ddebug
810 * object from the one the iterator currently points at,
811 * and returns a pointer to the new _ddebug. Returns
812 * NULL if the iterator has seen all the _ddebugs.
814 static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
816 if (iter->table == NULL)
818 if (++iter->idx == iter->table->num_ddebugs) {
819 /* iterate to next table */
821 if (list_is_last(&iter->table->link, &ddebug_tables)) {
825 iter->table = list_entry(iter->table->link.next,
826 struct ddebug_table, link);
828 return &iter->table->ddebugs[iter->idx];
832 * Seq_ops start method. Called at the start of every
833 * read() call from userspace. Takes the ddebug_lock and
834 * seeks the seq_file's iterator to the given position.
836 static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
838 struct ddebug_iter *iter = m->private;
842 mutex_lock(&ddebug_lock);
845 return SEQ_START_TOKEN;
848 dp = ddebug_iter_first(iter);
849 while (dp != NULL && --n > 0)
850 dp = ddebug_iter_next(iter);
855 * Seq_ops next method. Called several times within a read()
856 * call from userspace, with ddebug_lock held. Walks to the
857 * next _ddebug object with a special case for the header line.
859 static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
861 struct ddebug_iter *iter = m->private;
864 if (p == SEQ_START_TOKEN)
865 dp = ddebug_iter_first(iter);
867 dp = ddebug_iter_next(iter);
873 * Seq_ops show method. Called several times within a read()
874 * call from userspace, with ddebug_lock held. Formats the
875 * current _ddebug as a single human-readable line, with a
876 * special case for the header line.
878 static int ddebug_proc_show(struct seq_file *m, void *p)
880 struct ddebug_iter *iter = m->private;
881 struct _ddebug *dp = p;
882 struct flagsbuf flags;
884 if (p == SEQ_START_TOKEN) {
886 "# filename:lineno [module]function flags format\n");
890 seq_printf(m, "%s:%u [%s]%s =%s \"",
891 trim_prefix(dp->filename), dp->lineno,
892 iter->table->mod_name, dp->function,
893 ddebug_describe_flags(dp->flags, &flags));
894 seq_escape(m, dp->format, "\t\r\n\"");
901 * Seq_ops stop method. Called at the end of each read()
902 * call from userspace. Drops ddebug_lock.
904 static void ddebug_proc_stop(struct seq_file *m, void *p)
906 mutex_unlock(&ddebug_lock);
909 static const struct seq_operations ddebug_proc_seqops = {
910 .start = ddebug_proc_start,
911 .next = ddebug_proc_next,
912 .show = ddebug_proc_show,
913 .stop = ddebug_proc_stop
916 static int ddebug_proc_open(struct inode *inode, struct file *file)
918 vpr_info("called\n");
919 return seq_open_private(file, &ddebug_proc_seqops,
920 sizeof(struct ddebug_iter));
923 static const struct file_operations ddebug_proc_fops = {
924 .owner = THIS_MODULE,
925 .open = ddebug_proc_open,
928 .release = seq_release_private,
929 .write = ddebug_proc_write
932 static const struct proc_ops proc_fops = {
933 .proc_open = ddebug_proc_open,
934 .proc_read = seq_read,
935 .proc_lseek = seq_lseek,
936 .proc_release = seq_release_private,
937 .proc_write = ddebug_proc_write
941 * Allocate a new ddebug_table for the given module
942 * and add it to the global list.
944 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
947 struct ddebug_table *dt;
949 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
951 pr_err("error adding module: %s\n", name);
955 * For built-in modules, name lives in .rodata and is
956 * immortal. For loaded modules, name points at the name[]
957 * member of struct module, which lives at least as long as
958 * this struct ddebug_table.
964 mutex_lock(&ddebug_lock);
965 list_add(&dt->link, &ddebug_tables);
966 mutex_unlock(&ddebug_lock);
968 v2pr_info("%3u debug prints in module %s\n", n, dt->mod_name);
972 /* helper for ddebug_dyndbg_(boot|module)_param_cb */
973 static int ddebug_dyndbg_param_cb(char *param, char *val,
974 const char *modname, int on_err)
978 sep = strchr(param, '.');
980 /* needed only for ddebug_dyndbg_boot_param_cb */
985 if (strcmp(param, "dyndbg"))
986 return on_err; /* determined by caller */
988 ddebug_exec_queries((val ? val : "+p"), modname);
990 return 0; /* query failure shouldnt stop module load */
993 /* handle both dyndbg and $module.dyndbg params at boot */
994 static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
995 const char *unused, void *arg)
997 vpr_info("%s=\"%s\"\n", param, val);
998 return ddebug_dyndbg_param_cb(param, val, NULL, 0);
1002 * modprobe foo finds foo.params in boot-args, strips "foo.", and
1003 * passes them to load_module(). This callback gets unknown params,
1004 * processes dyndbg params, rejects others.
1006 int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
1008 vpr_info("module: %s %s=\"%s\"\n", module, param, val);
1009 return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
1012 static void ddebug_table_free(struct ddebug_table *dt)
1014 list_del_init(&dt->link);
1019 * Called in response to a module being unloaded. Removes
1020 * any ddebug_table's which point at the module.
1022 int ddebug_remove_module(const char *mod_name)
1024 struct ddebug_table *dt, *nextdt;
1027 v2pr_info("removing module \"%s\"\n", mod_name);
1029 mutex_lock(&ddebug_lock);
1030 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
1031 if (dt->mod_name == mod_name) {
1032 ddebug_table_free(dt);
1037 mutex_unlock(&ddebug_lock);
1041 static void ddebug_remove_all_tables(void)
1043 mutex_lock(&ddebug_lock);
1044 while (!list_empty(&ddebug_tables)) {
1045 struct ddebug_table *dt = list_entry(ddebug_tables.next,
1046 struct ddebug_table,
1048 ddebug_table_free(dt);
1050 mutex_unlock(&ddebug_lock);
1053 static __initdata int ddebug_init_success;
1055 static int __init dynamic_debug_init_control(void)
1057 struct proc_dir_entry *procfs_dir;
1058 struct dentry *debugfs_dir;
1060 if (!ddebug_init_success)
1063 /* Create the control file in debugfs if it is enabled */
1064 if (debugfs_initialized()) {
1065 debugfs_dir = debugfs_create_dir("dynamic_debug", NULL);
1066 debugfs_create_file("control", 0644, debugfs_dir, NULL,
1070 /* Also create the control file in procfs */
1071 procfs_dir = proc_mkdir("dynamic_debug", NULL);
1073 proc_create("control", 0644, procfs_dir, &proc_fops);
1078 static int __init dynamic_debug_init(void)
1080 struct _ddebug *iter, *iter_start;
1081 const char *modname = NULL;
1084 int n = 0, entries = 0, modct = 0;
1086 if (&__start___dyndbg == &__stop___dyndbg) {
1087 if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
1088 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1091 pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
1092 ddebug_init_success = 1;
1095 iter = __start___dyndbg;
1096 modname = iter->modname;
1098 for (; iter < __stop___dyndbg; iter++) {
1100 if (strcmp(modname, iter->modname)) {
1102 ret = ddebug_add_module(iter_start, n, modname);
1106 modname = iter->modname;
1111 ret = ddebug_add_module(iter_start, n, modname);
1115 ddebug_init_success = 1;
1116 vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in __dyndbg section\n",
1117 modct, entries, (int)(modct * sizeof(struct ddebug_table)),
1118 (int)(entries * sizeof(struct _ddebug)));
1120 /* apply ddebug_query boot param, dont unload tables on err */
1121 if (ddebug_setup_string[0] != '\0') {
1122 pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n");
1123 ret = ddebug_exec_queries(ddebug_setup_string, NULL);
1125 pr_warn("Invalid ddebug boot param %s\n",
1126 ddebug_setup_string);
1128 pr_info("%d changes by ddebug_query\n", ret);
1130 /* now that ddebug tables are loaded, process all boot args
1131 * again to find and activate queries given in dyndbg params.
1132 * While this has already been done for known boot params, it
1133 * ignored the unknown ones (dyndbg in particular). Reusing
1134 * parse_args avoids ad-hoc parsing. This will also attempt
1135 * to activate queries for not-yet-loaded modules, which is
1136 * slightly noisy if verbose, but harmless.
1138 cmdline = kstrdup(saved_command_line, GFP_KERNEL);
1139 parse_args("dyndbg params", cmdline, NULL,
1140 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
1145 ddebug_remove_all_tables();
1148 /* Allow early initialization for boot messages via boot param */
1149 early_initcall(dynamic_debug_init);
1151 /* Debugfs setup must be done later */
1152 fs_initcall(dynamic_debug_init_control);