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)
594 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
596 pos += snprintf(buf + pos, remaining(pos), "<intr> ");
598 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
599 task_pid_vnr(current));
602 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
603 pos += snprintf(buf + pos, remaining(pos), "%s:",
605 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
606 pos += snprintf(buf + pos, remaining(pos), "%s:",
608 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
609 pos += snprintf(buf + pos, remaining(pos), "%d:",
611 if (pos - pos_after_tid)
612 pos += snprintf(buf + pos, remaining(pos), " ");
613 if (pos >= PREFIX_SIZE)
614 buf[PREFIX_SIZE - 1] = '\0';
619 static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)
621 if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_ANY))
622 return __dynamic_emit_prefix(desc, buf);
626 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
629 struct va_format vaf;
630 char buf[PREFIX_SIZE] = "";
640 printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
644 EXPORT_SYMBOL(__dynamic_pr_debug);
646 void __dynamic_dev_dbg(struct _ddebug *descriptor,
647 const struct device *dev, const char *fmt, ...)
649 struct va_format vaf;
661 printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
663 char buf[PREFIX_SIZE] = "";
665 dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
666 dynamic_emit_prefix(descriptor, buf),
667 dev_driver_string(dev), dev_name(dev),
673 EXPORT_SYMBOL(__dynamic_dev_dbg);
677 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
678 const struct net_device *dev, const char *fmt, ...)
680 struct va_format vaf;
691 if (dev && dev->dev.parent) {
692 char buf[PREFIX_SIZE] = "";
694 dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
696 dynamic_emit_prefix(descriptor, buf),
697 dev_driver_string(dev->dev.parent),
698 dev_name(dev->dev.parent),
699 netdev_name(dev), netdev_reg_state(dev),
702 printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
703 netdev_reg_state(dev), &vaf);
705 printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
710 EXPORT_SYMBOL(__dynamic_netdev_dbg);
714 #if IS_ENABLED(CONFIG_INFINIBAND)
716 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
717 const struct ib_device *ibdev, const char *fmt, ...)
719 struct va_format vaf;
727 if (ibdev && ibdev->dev.parent) {
728 char buf[PREFIX_SIZE] = "";
730 dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
732 dynamic_emit_prefix(descriptor, buf),
733 dev_driver_string(ibdev->dev.parent),
734 dev_name(ibdev->dev.parent),
735 dev_name(&ibdev->dev),
738 printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
740 printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
745 EXPORT_SYMBOL(__dynamic_ibdev_dbg);
749 #define DDEBUG_STRING_SIZE 1024
750 static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
752 static __init int ddebug_setup_query(char *str)
754 if (strlen(str) >= DDEBUG_STRING_SIZE) {
755 pr_warn("ddebug boot param string too large\n");
758 strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
762 __setup("ddebug_query=", ddebug_setup_query);
765 * Install a noop handler to make dyndbg look like a normal kernel cli param.
766 * This avoids warnings about dyndbg being an unknown cli param when supplied
769 static __init int dyndbg_setup(char *str)
774 __setup("dyndbg=", dyndbg_setup);
777 * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
778 * command text from userspace, parses and executes it.
780 #define USER_BUF_PAGE 4096
781 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
782 size_t len, loff_t *offp)
789 if (len > USER_BUF_PAGE - 1) {
790 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
793 tmpbuf = memdup_user_nul(ubuf, len);
795 return PTR_ERR(tmpbuf);
796 vpr_info("read %d bytes from userspace\n", (int)len);
798 ret = ddebug_exec_queries(tmpbuf, NULL);
808 * Set the iterator to point to the first _ddebug object
809 * and return a pointer to that first object. Returns
810 * NULL if there are no _ddebugs at all.
812 static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
814 if (list_empty(&ddebug_tables)) {
819 iter->table = list_entry(ddebug_tables.next,
820 struct ddebug_table, link);
822 return &iter->table->ddebugs[iter->idx];
826 * Advance the iterator to point to the next _ddebug
827 * object from the one the iterator currently points at,
828 * and returns a pointer to the new _ddebug. Returns
829 * NULL if the iterator has seen all the _ddebugs.
831 static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
833 if (iter->table == NULL)
835 if (++iter->idx == iter->table->num_ddebugs) {
836 /* iterate to next table */
838 if (list_is_last(&iter->table->link, &ddebug_tables)) {
842 iter->table = list_entry(iter->table->link.next,
843 struct ddebug_table, link);
845 return &iter->table->ddebugs[iter->idx];
849 * Seq_ops start method. Called at the start of every
850 * read() call from userspace. Takes the ddebug_lock and
851 * seeks the seq_file's iterator to the given position.
853 static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
855 struct ddebug_iter *iter = m->private;
859 mutex_lock(&ddebug_lock);
862 return SEQ_START_TOKEN;
865 dp = ddebug_iter_first(iter);
866 while (dp != NULL && --n > 0)
867 dp = ddebug_iter_next(iter);
872 * Seq_ops next method. Called several times within a read()
873 * call from userspace, with ddebug_lock held. Walks to the
874 * next _ddebug object with a special case for the header line.
876 static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
878 struct ddebug_iter *iter = m->private;
881 if (p == SEQ_START_TOKEN)
882 dp = ddebug_iter_first(iter);
884 dp = ddebug_iter_next(iter);
890 * Seq_ops show method. Called several times within a read()
891 * call from userspace, with ddebug_lock held. Formats the
892 * current _ddebug as a single human-readable line, with a
893 * special case for the header line.
895 static int ddebug_proc_show(struct seq_file *m, void *p)
897 struct ddebug_iter *iter = m->private;
898 struct _ddebug *dp = p;
899 struct flagsbuf flags;
901 if (p == SEQ_START_TOKEN) {
903 "# filename:lineno [module]function flags format\n");
907 seq_printf(m, "%s:%u [%s]%s =%s \"",
908 trim_prefix(dp->filename), dp->lineno,
909 iter->table->mod_name, dp->function,
910 ddebug_describe_flags(dp->flags, &flags));
911 seq_escape(m, dp->format, "\t\r\n\"");
918 * Seq_ops stop method. Called at the end of each read()
919 * call from userspace. Drops ddebug_lock.
921 static void ddebug_proc_stop(struct seq_file *m, void *p)
923 mutex_unlock(&ddebug_lock);
926 static const struct seq_operations ddebug_proc_seqops = {
927 .start = ddebug_proc_start,
928 .next = ddebug_proc_next,
929 .show = ddebug_proc_show,
930 .stop = ddebug_proc_stop
933 static int ddebug_proc_open(struct inode *inode, struct file *file)
935 return seq_open_private(file, &ddebug_proc_seqops,
936 sizeof(struct ddebug_iter));
939 static const struct file_operations ddebug_proc_fops = {
940 .owner = THIS_MODULE,
941 .open = ddebug_proc_open,
944 .release = seq_release_private,
945 .write = ddebug_proc_write
948 static const struct proc_ops proc_fops = {
949 .proc_open = ddebug_proc_open,
950 .proc_read = seq_read,
951 .proc_lseek = seq_lseek,
952 .proc_release = seq_release_private,
953 .proc_write = ddebug_proc_write
957 * Allocate a new ddebug_table for the given module
958 * and add it to the global list.
960 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
963 struct ddebug_table *dt;
965 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
967 pr_err("error adding module: %s\n", name);
971 * For built-in modules, name lives in .rodata and is
972 * immortal. For loaded modules, name points at the name[]
973 * member of struct module, which lives at least as long as
974 * this struct ddebug_table.
980 mutex_lock(&ddebug_lock);
981 list_add(&dt->link, &ddebug_tables);
982 mutex_unlock(&ddebug_lock);
984 v2pr_info("%3u debug prints in module %s\n", n, dt->mod_name);
988 /* helper for ddebug_dyndbg_(boot|module)_param_cb */
989 static int ddebug_dyndbg_param_cb(char *param, char *val,
990 const char *modname, int on_err)
994 sep = strchr(param, '.');
996 /* needed only for ddebug_dyndbg_boot_param_cb */
1001 if (strcmp(param, "dyndbg"))
1002 return on_err; /* determined by caller */
1004 ddebug_exec_queries((val ? val : "+p"), modname);
1006 return 0; /* query failure shouldn't stop module load */
1009 /* handle both dyndbg and $module.dyndbg params at boot */
1010 static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
1011 const char *unused, void *arg)
1013 vpr_info("%s=\"%s\"\n", param, val);
1014 return ddebug_dyndbg_param_cb(param, val, NULL, 0);
1018 * modprobe foo finds foo.params in boot-args, strips "foo.", and
1019 * passes them to load_module(). This callback gets unknown params,
1020 * processes dyndbg params, rejects others.
1022 int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
1024 vpr_info("module: %s %s=\"%s\"\n", module, param, val);
1025 return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
1028 static void ddebug_table_free(struct ddebug_table *dt)
1030 list_del_init(&dt->link);
1035 * Called in response to a module being unloaded. Removes
1036 * any ddebug_table's which point at the module.
1038 int ddebug_remove_module(const char *mod_name)
1040 struct ddebug_table *dt, *nextdt;
1043 v2pr_info("removing module \"%s\"\n", mod_name);
1045 mutex_lock(&ddebug_lock);
1046 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
1047 if (dt->mod_name == mod_name) {
1048 ddebug_table_free(dt);
1053 mutex_unlock(&ddebug_lock);
1057 static void ddebug_remove_all_tables(void)
1059 mutex_lock(&ddebug_lock);
1060 while (!list_empty(&ddebug_tables)) {
1061 struct ddebug_table *dt = list_entry(ddebug_tables.next,
1062 struct ddebug_table,
1064 ddebug_table_free(dt);
1066 mutex_unlock(&ddebug_lock);
1069 static __initdata int ddebug_init_success;
1071 static int __init dynamic_debug_init_control(void)
1073 struct proc_dir_entry *procfs_dir;
1074 struct dentry *debugfs_dir;
1076 if (!ddebug_init_success)
1079 /* Create the control file in debugfs if it is enabled */
1080 if (debugfs_initialized()) {
1081 debugfs_dir = debugfs_create_dir("dynamic_debug", NULL);
1082 debugfs_create_file("control", 0644, debugfs_dir, NULL,
1086 /* Also create the control file in procfs */
1087 procfs_dir = proc_mkdir("dynamic_debug", NULL);
1089 proc_create("control", 0644, procfs_dir, &proc_fops);
1094 static int __init dynamic_debug_init(void)
1096 struct _ddebug *iter, *iter_start;
1097 const char *modname = NULL;
1100 int n = 0, entries = 0, modct = 0;
1102 if (&__start___dyndbg == &__stop___dyndbg) {
1103 if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
1104 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1107 pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
1108 ddebug_init_success = 1;
1111 iter = __start___dyndbg;
1112 modname = iter->modname;
1114 for (; iter < __stop___dyndbg; iter++) {
1116 if (strcmp(modname, iter->modname)) {
1118 ret = ddebug_add_module(iter_start, n, modname);
1122 modname = iter->modname;
1127 ret = ddebug_add_module(iter_start, n, modname);
1131 ddebug_init_success = 1;
1132 vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg section\n",
1133 entries, modct, (int)((modct * sizeof(struct ddebug_table)) >> 10),
1134 (int)((entries * sizeof(struct _ddebug)) >> 10));
1136 /* apply ddebug_query boot param, dont unload tables on err */
1137 if (ddebug_setup_string[0] != '\0') {
1138 pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n");
1139 ret = ddebug_exec_queries(ddebug_setup_string, NULL);
1141 pr_warn("Invalid ddebug boot param %s\n",
1142 ddebug_setup_string);
1144 pr_info("%d changes by ddebug_query\n", ret);
1146 /* now that ddebug tables are loaded, process all boot args
1147 * again to find and activate queries given in dyndbg params.
1148 * While this has already been done for known boot params, it
1149 * ignored the unknown ones (dyndbg in particular). Reusing
1150 * parse_args avoids ad-hoc parsing. This will also attempt
1151 * to activate queries for not-yet-loaded modules, which is
1152 * slightly noisy if verbose, but harmless.
1154 cmdline = kstrdup(saved_command_line, GFP_KERNEL);
1155 parse_args("dyndbg params", cmdline, NULL,
1156 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
1161 ddebug_remove_all_tables();
1164 /* Allow early initialization for boot messages via boot param */
1165 early_initcall(dynamic_debug_init);
1167 /* Debugfs setup must be done later */
1168 fs_initcall(dynamic_debug_init_control);