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 const struct { unsigned flag:8; char opt_char; } opt_array[] = {
92 { _DPRINTK_FLAGS_PRINT, 'p' },
93 { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
94 { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
95 { _DPRINTK_FLAGS_INCL_SOURCENAME, 's' },
96 { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
97 { _DPRINTK_FLAGS_INCL_TID, 't' },
98 { _DPRINTK_FLAGS_NONE, '_' },
101 struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; };
103 /* format a string into buf[] which describes the _ddebug's flags */
104 static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb)
109 for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
110 if (flags & opt_array[i].flag)
111 *p++ = opt_array[i].opt_char;
119 #define vnpr_info(lvl, fmt, ...) \
121 if (verbose >= lvl) \
122 pr_info(fmt, ##__VA_ARGS__); \
125 #define vpr_info(fmt, ...) vnpr_info(1, fmt, ##__VA_ARGS__)
126 #define v2pr_info(fmt, ...) vnpr_info(2, fmt, ##__VA_ARGS__)
127 #define v3pr_info(fmt, ...) vnpr_info(3, fmt, ##__VA_ARGS__)
128 #define v4pr_info(fmt, ...) vnpr_info(4, fmt, ##__VA_ARGS__)
130 static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
132 /* trim any trailing newlines */
136 fmtlen = strlen(query->format);
137 while (fmtlen && query->format[fmtlen - 1] == '\n')
141 v3pr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u class=%s\n",
143 query->function ?: "",
144 query->filename ?: "",
146 fmtlen, query->format ?: "",
147 query->first_lineno, query->last_lineno, query->class_string);
150 static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
151 const char *class_string, int *class_id)
153 struct ddebug_class_map *map;
156 list_for_each_entry(map, &dt->maps, link) {
157 idx = match_string(map->class_names, map->length, class_string);
159 *class_id = idx + map->base;
167 #define __outvar /* filled by callee */
169 * Search the tables for _ddebug's which match the given `query' and
170 * apply the `flags' and `mask' to them. Returns number of matching
171 * callsites, normally the same as number of changes. If verbose,
172 * logs the changes. Takes ddebug_lock.
174 static int ddebug_change(const struct ddebug_query *query,
175 struct flag_settings *modifiers)
178 struct ddebug_table *dt;
179 unsigned int newflags;
180 unsigned int nfound = 0;
181 struct flagsbuf fbuf, nbuf;
182 struct ddebug_class_map *map = NULL;
183 int __outvar valid_class;
185 /* search for matching ddebugs */
186 mutex_lock(&ddebug_lock);
187 list_for_each_entry(dt, &ddebug_tables, link) {
189 /* match against the module name */
191 !match_wildcard(query->module, dt->mod_name))
194 if (query->class_string) {
195 map = ddebug_find_valid_class(dt, query->class_string, &valid_class);
199 /* constrain query, do not touch class'd callsites */
200 valid_class = _DPRINTK_CLASS_DFLT;
203 for (i = 0; i < dt->num_ddebugs; i++) {
204 struct _ddebug *dp = &dt->ddebugs[i];
206 /* match site against query-class */
207 if (dp->class_id != valid_class)
210 /* match against the source filename */
211 if (query->filename &&
212 !match_wildcard(query->filename, dp->filename) &&
213 !match_wildcard(query->filename,
214 kbasename(dp->filename)) &&
215 !match_wildcard(query->filename,
216 trim_prefix(dp->filename)))
219 /* match against the function */
220 if (query->function &&
221 !match_wildcard(query->function, dp->function))
224 /* match against the format */
226 if (*query->format == '^') {
228 /* anchored search. match must be at beginning */
229 p = strstr(dp->format, query->format+1);
232 } else if (!strstr(dp->format, query->format))
236 /* match against the line number range */
237 if (query->first_lineno &&
238 dp->lineno < query->first_lineno)
240 if (query->last_lineno &&
241 dp->lineno > query->last_lineno)
246 newflags = (dp->flags & modifiers->mask) | modifiers->flags;
247 if (newflags == dp->flags)
249 #ifdef CONFIG_JUMP_LABEL
250 if (dp->flags & _DPRINTK_FLAGS_PRINT) {
251 if (!(newflags & _DPRINTK_FLAGS_PRINT))
252 static_branch_disable(&dp->key.dd_key_true);
253 } else if (newflags & _DPRINTK_FLAGS_PRINT) {
254 static_branch_enable(&dp->key.dd_key_true);
257 v4pr_info("changed %s:%d [%s]%s %s => %s\n",
258 trim_prefix(dp->filename), dp->lineno,
259 dt->mod_name, dp->function,
260 ddebug_describe_flags(dp->flags, &fbuf),
261 ddebug_describe_flags(newflags, &nbuf));
262 dp->flags = newflags;
265 mutex_unlock(&ddebug_lock);
267 if (!nfound && verbose)
268 pr_info("no matches for query\n");
274 * Split the buffer `buf' into space-separated words.
275 * Handles simple " and ' quoting, i.e. without nested,
276 * embedded or escaped \". Return the number of words
279 static int ddebug_tokenize(char *buf, char *words[], int maxwords)
286 /* Skip leading whitespace */
287 buf = skip_spaces(buf);
289 break; /* oh, it was trailing whitespace */
291 break; /* token starts comment, skip rest of line */
293 /* find `end' of word, whitespace separated or quoted */
294 if (*buf == '"' || *buf == '\'') {
296 for (end = buf; *end && *end != quote; end++)
299 pr_err("unclosed quote: %s\n", buf);
300 return -EINVAL; /* unclosed quote */
303 for (end = buf; *end && !isspace(*end); end++)
308 /* `buf' is start of word, `end' is one past its end */
309 if (nwords == maxwords) {
310 pr_err("too many words, legal max <=%d\n", maxwords);
311 return -EINVAL; /* ran out of words[] before bytes */
314 *end++ = '\0'; /* terminate the word */
315 words[nwords++] = buf;
321 pr_info("split into words:");
322 for (i = 0; i < nwords; i++)
323 pr_cont(" \"%s\"", words[i]);
331 * Parse a single line number. Note that the empty string ""
332 * is treated as a special case and converted to zero, which
333 * is later treated as a "don't care" value.
335 static inline int parse_lineno(const char *str, unsigned int *val)
342 if (kstrtouint(str, 10, val) < 0) {
343 pr_err("bad line-number: %s\n", str);
349 static int parse_linerange(struct ddebug_query *query, const char *first)
351 char *last = strchr(first, '-');
353 if (query->first_lineno || query->last_lineno) {
354 pr_err("match-spec: line used 2x\n");
359 if (parse_lineno(first, &query->first_lineno) < 0)
362 /* range <first>-<last> */
363 if (parse_lineno(last, &query->last_lineno) < 0)
366 /* special case for last lineno not specified */
367 if (query->last_lineno == 0)
368 query->last_lineno = UINT_MAX;
370 if (query->last_lineno < query->first_lineno) {
371 pr_err("last-line:%d < 1st-line:%d\n",
373 query->first_lineno);
377 query->last_lineno = query->first_lineno;
379 v3pr_info("parsed line %d-%d\n", query->first_lineno,
384 static int check_set(const char **dest, char *src, char *name)
390 pr_err("match-spec:%s val:%s overridden by %s\n",
398 * Parse words[] as a ddebug query specification, which is a series
399 * of (keyword, value) pairs chosen from these possibilities:
401 * func <function-name>
402 * file <full-pathname>
403 * file <base-filename>
404 * module <module-name>
405 * format <escaped-string-to-find-in-format>
407 * line <first-lineno>-<last-lineno> // where either may be empty
409 * Only 1 of each type is allowed.
410 * Returns 0 on success, <0 on error.
412 static int ddebug_parse_query(char *words[], int nwords,
413 struct ddebug_query *query, const char *modname)
419 /* check we have an even number of words */
420 if (nwords % 2 != 0) {
421 pr_err("expecting pairs of match-spec <value>\n");
425 for (i = 0; i < nwords; i += 2) {
426 char *keyword = words[i];
427 char *arg = words[i+1];
429 if (!strcmp(keyword, "func")) {
430 rc = check_set(&query->function, arg, "func");
431 } else if (!strcmp(keyword, "file")) {
432 if (check_set(&query->filename, arg, "file"))
435 /* tail :$info is function or line-range */
436 fline = strchr(query->filename, ':');
440 if (isalpha(*fline) || *fline == '*' || *fline == '?') {
441 /* take as function name */
442 if (check_set(&query->function, fline, "func"))
445 if (parse_linerange(query, fline))
448 } else if (!strcmp(keyword, "module")) {
449 rc = check_set(&query->module, arg, "module");
450 } else if (!strcmp(keyword, "format")) {
451 string_unescape_inplace(arg, UNESCAPE_SPACE |
454 rc = check_set(&query->format, arg, "format");
455 } else if (!strcmp(keyword, "line")) {
456 if (parse_linerange(query, arg))
458 } else if (!strcmp(keyword, "class")) {
459 rc = check_set(&query->class_string, arg, "class");
461 pr_err("unknown keyword \"%s\"\n", keyword);
467 if (!query->module && modname)
469 * support $modname.dyndbg=<multiple queries>, when
470 * not given in the query itself
472 query->module = modname;
474 vpr_info_dq(query, "parsed");
479 * Parse `str' as a flags specification, format [-+=][p]+.
480 * Sets up *maskp and *flagsp to be used when changing the
481 * flags fields of matched _ddebug's. Returns 0 on success
484 static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
495 pr_err("bad flag-op %c, at start of %s\n", *str, str);
498 v3pr_info("op='%c'\n", op);
500 for (; *str ; ++str) {
501 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
502 if (*str == opt_array[i].opt_char) {
503 modifiers->flags |= opt_array[i].flag;
508 pr_err("unknown flag '%c'\n", *str);
512 v3pr_info("flags=0x%x\n", modifiers->flags);
514 /* calculate final flags, mask based upon op */
517 /* modifiers->flags already set */
521 modifiers->mask = ~0U;
524 modifiers->mask = ~modifiers->flags;
525 modifiers->flags = 0;
528 v3pr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
533 static int ddebug_exec_query(char *query_string, const char *modname)
535 struct flag_settings modifiers = {};
536 struct ddebug_query query = {};
539 char *words[MAXWORDS];
541 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
543 pr_err("tokenize failed\n");
546 /* check flags 1st (last arg) so query is pairs of spec,val */
547 if (ddebug_parse_flags(words[nwords-1], &modifiers)) {
548 pr_err("flags parse failed\n");
551 if (ddebug_parse_query(words, nwords-1, &query, modname)) {
552 pr_err("query parse failed\n");
555 /* actually go and implement the change */
556 nfound = ddebug_change(&query, &modifiers);
557 vpr_info_dq(&query, nfound ? "applied" : "no-match");
562 /* handle multiple queries in query string, continue on error, return
563 last error or number of matching callsites. Module name is either
564 in param (for boot arg) or perhaps in query string.
566 static int ddebug_exec_queries(char *query, const char *modname)
569 int i, errs = 0, exitcode = 0, rc, nfound = 0;
571 for (i = 0; query; query = split) {
572 split = strpbrk(query, ";\n");
576 query = skip_spaces(query);
577 if (!query || !*query || *query == '#')
580 vpr_info("query %d: \"%s\" mod:%s\n", i, query, modname ?: "*");
582 rc = ddebug_exec_query(query, modname);
592 v2pr_info("processed %d queries, with %d matches, %d errs\n",
600 /* apply a new bitmap to the sys-knob's current bit-state */
601 static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
602 unsigned long *new_bits, unsigned long *old_bits)
604 #define QUERY_SIZE 128
605 char query[QUERY_SIZE];
606 const struct ddebug_class_map *map = dcp->map;
610 v2pr_info("apply: 0x%lx to: 0x%lx\n", *new_bits, *old_bits);
612 for (bi = 0; bi < map->length; bi++) {
613 if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
616 snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
617 test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
619 ct = ddebug_exec_queries(query, NULL);
622 v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
623 ct, map->class_names[bi], *new_bits);
628 /* stub to later conditionally add "$module." prefix where not already done */
629 #define KP_NAME(kp) kp->name
631 #define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
633 /* accept comma-separated-list of [+-] classnames */
634 static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp)
636 const struct ddebug_class_param *dcp = kp->arg;
637 const struct ddebug_class_map *map = dcp->map;
638 unsigned long curr_bits, old_bits;
639 char *cl_str, *p, *tmp;
640 int cls_id, totct = 0;
643 cl_str = tmp = kstrdup_and_replace(instr, '\n', '\0', GFP_KERNEL);
647 /* start with previously set state-bits, then modify */
648 curr_bits = old_bits = *dcp->bits;
649 vpr_info("\"%s\" > %s:0x%lx\n", cl_str, KP_NAME(kp), curr_bits);
651 for (; cl_str; cl_str = p) {
652 p = strchr(cl_str, ',');
656 if (*cl_str == '-') {
664 cls_id = match_string(map->class_names, map->length, cl_str);
666 pr_err("%s unknown to %s\n", cl_str, KP_NAME(kp));
670 /* have one or more valid class_ids of one *_NAMES type */
671 switch (map->map_type) {
672 case DD_CLASS_TYPE_DISJOINT_NAMES:
673 /* the +/- pertains to a single bit */
674 if (test_bit(cls_id, &curr_bits) == wanted) {
675 v3pr_info("no change on %s\n", cl_str);
678 curr_bits ^= BIT(cls_id);
679 totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits);
680 *dcp->bits = curr_bits;
681 v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
682 map->class_names[cls_id]);
684 case DD_CLASS_TYPE_LEVEL_NAMES:
685 /* cls_id = N in 0..max. wanted +/- determines N or N-1 */
686 old_bits = CLASSMAP_BITMASK(*dcp->lvl);
687 curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
689 totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits);
690 *dcp->lvl = (cls_id + (wanted ? 1 : 0));
691 v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
692 map->class_names[cls_id], old_bits, curr_bits);
695 pr_err("illegal map-type value %d\n", map->map_type);
699 vpr_info("total matches: %d\n", totct);
704 * param_set_dyndbg_classes - class FOO >control
705 * @instr: string echo>d to sysfs, input depends on map_type
706 * @kp: kp->arg has state: bits/lvl, map, map_type
708 * Enable/disable prdbgs by their class, as given in the arguments to
709 * DECLARE_DYNDBG_CLASSMAP. For LEVEL map-types, enforce relative
712 * Returns: 0 or <0 if error.
714 int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
716 const struct ddebug_class_param *dcp = kp->arg;
717 const struct ddebug_class_map *map = dcp->map;
718 unsigned long inrep, new_bits, old_bits;
721 switch (map->map_type) {
723 case DD_CLASS_TYPE_DISJOINT_NAMES:
724 case DD_CLASS_TYPE_LEVEL_NAMES:
725 /* handle [+-]classnames list separately, we are done here */
726 return param_set_dyndbg_classnames(instr, kp);
728 case DD_CLASS_TYPE_DISJOINT_BITS:
729 case DD_CLASS_TYPE_LEVEL_NUM:
730 /* numeric input, accept and fall-thru */
731 rc = kstrtoul(instr, 0, &inrep);
733 pr_err("expecting numeric input: %s > %s\n", instr, KP_NAME(kp));
738 pr_err("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
742 /* only _BITS,_NUM (numeric) map-types get here */
743 switch (map->map_type) {
744 case DD_CLASS_TYPE_DISJOINT_BITS:
745 /* expect bits. mask and warn if too many */
746 if (inrep & ~CLASSMAP_BITMASK(map->length)) {
747 pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
748 KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
749 inrep &= CLASSMAP_BITMASK(map->length);
751 v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
752 totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits);
755 case DD_CLASS_TYPE_LEVEL_NUM:
756 /* input is bitpos, of highest verbosity to be enabled */
757 if (inrep > map->length) {
758 pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
759 KP_NAME(kp), inrep, map->length);
762 old_bits = CLASSMAP_BITMASK(*dcp->lvl);
763 new_bits = CLASSMAP_BITMASK(inrep);
764 v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
765 totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits);
769 pr_warn("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
771 vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
774 EXPORT_SYMBOL(param_set_dyndbg_classes);
777 * param_get_dyndbg_classes - classes reader
778 * @buffer: string description of controlled bits -> classes
779 * @kp: kp->arg has state: bits, map
781 * Reads last written state, underlying prdbg state may have been
782 * altered by direct >control. Displays 0x for DISJOINT, 0-N for
783 * LEVEL Returns: #chars written or <0 on error
785 int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
787 const struct ddebug_class_param *dcp = kp->arg;
788 const struct ddebug_class_map *map = dcp->map;
790 switch (map->map_type) {
792 case DD_CLASS_TYPE_DISJOINT_NAMES:
793 case DD_CLASS_TYPE_DISJOINT_BITS:
794 return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
796 case DD_CLASS_TYPE_LEVEL_NAMES:
797 case DD_CLASS_TYPE_LEVEL_NUM:
798 return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
803 EXPORT_SYMBOL(param_get_dyndbg_classes);
805 const struct kernel_param_ops param_ops_dyndbg_classes = {
806 .set = param_set_dyndbg_classes,
807 .get = param_get_dyndbg_classes,
809 EXPORT_SYMBOL(param_ops_dyndbg_classes);
811 #define PREFIX_SIZE 128
813 static int remaining(int wrote)
815 if (PREFIX_SIZE - wrote > 0)
816 return PREFIX_SIZE - wrote;
820 static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
825 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
827 pos += snprintf(buf + pos, remaining(pos), "<intr> ");
829 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
830 task_pid_vnr(current));
833 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
834 pos += snprintf(buf + pos, remaining(pos), "%s:",
836 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
837 pos += snprintf(buf + pos, remaining(pos), "%s:",
839 if (desc->flags & _DPRINTK_FLAGS_INCL_SOURCENAME)
840 pos += snprintf(buf + pos, remaining(pos), "%s:",
841 trim_prefix(desc->filename));
842 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
843 pos += snprintf(buf + pos, remaining(pos), "%d:",
845 if (pos - pos_after_tid)
846 pos += snprintf(buf + pos, remaining(pos), " ");
847 if (pos >= PREFIX_SIZE)
848 buf[PREFIX_SIZE - 1] = '\0';
853 static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)
855 if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_ANY))
856 return __dynamic_emit_prefix(desc, buf);
860 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
863 struct va_format vaf;
864 char buf[PREFIX_SIZE] = "";
874 printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
878 EXPORT_SYMBOL(__dynamic_pr_debug);
880 void __dynamic_dev_dbg(struct _ddebug *descriptor,
881 const struct device *dev, const char *fmt, ...)
883 struct va_format vaf;
895 printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
897 char buf[PREFIX_SIZE] = "";
899 dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
900 dynamic_emit_prefix(descriptor, buf),
901 dev_driver_string(dev), dev_name(dev),
907 EXPORT_SYMBOL(__dynamic_dev_dbg);
911 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
912 const struct net_device *dev, const char *fmt, ...)
914 struct va_format vaf;
925 if (dev && dev->dev.parent) {
926 char buf[PREFIX_SIZE] = "";
928 dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
930 dynamic_emit_prefix(descriptor, buf),
931 dev_driver_string(dev->dev.parent),
932 dev_name(dev->dev.parent),
933 netdev_name(dev), netdev_reg_state(dev),
936 printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
937 netdev_reg_state(dev), &vaf);
939 printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
944 EXPORT_SYMBOL(__dynamic_netdev_dbg);
948 #if IS_ENABLED(CONFIG_INFINIBAND)
950 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
951 const struct ib_device *ibdev, const char *fmt, ...)
953 struct va_format vaf;
961 if (ibdev && ibdev->dev.parent) {
962 char buf[PREFIX_SIZE] = "";
964 dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
966 dynamic_emit_prefix(descriptor, buf),
967 dev_driver_string(ibdev->dev.parent),
968 dev_name(ibdev->dev.parent),
969 dev_name(&ibdev->dev),
972 printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
974 printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
979 EXPORT_SYMBOL(__dynamic_ibdev_dbg);
984 * Install a noop handler to make dyndbg look like a normal kernel cli param.
985 * This avoids warnings about dyndbg being an unknown cli param when supplied
988 static __init int dyndbg_setup(char *str)
993 __setup("dyndbg=", dyndbg_setup);
996 * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
997 * command text from userspace, parses and executes it.
999 #define USER_BUF_PAGE 4096
1000 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
1001 size_t len, loff_t *offp)
1008 if (len > USER_BUF_PAGE - 1) {
1009 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
1012 tmpbuf = memdup_user_nul(ubuf, len);
1014 return PTR_ERR(tmpbuf);
1015 v2pr_info("read %zu bytes from userspace\n", len);
1017 ret = ddebug_exec_queries(tmpbuf, NULL);
1027 * Set the iterator to point to the first _ddebug object
1028 * and return a pointer to that first object. Returns
1029 * NULL if there are no _ddebugs at all.
1031 static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
1033 if (list_empty(&ddebug_tables)) {
1037 iter->table = list_entry(ddebug_tables.next,
1038 struct ddebug_table, link);
1039 iter->idx = iter->table->num_ddebugs;
1040 return &iter->table->ddebugs[--iter->idx];
1044 * Advance the iterator to point to the next _ddebug
1045 * object from the one the iterator currently points at,
1046 * and returns a pointer to the new _ddebug. Returns
1047 * NULL if the iterator has seen all the _ddebugs.
1049 static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
1051 if (iter->table == NULL)
1053 if (--iter->idx < 0) {
1054 /* iterate to next table */
1055 if (list_is_last(&iter->table->link, &ddebug_tables)) {
1059 iter->table = list_entry(iter->table->link.next,
1060 struct ddebug_table, link);
1061 iter->idx = iter->table->num_ddebugs;
1064 return &iter->table->ddebugs[iter->idx];
1068 * Seq_ops start method. Called at the start of every
1069 * read() call from userspace. Takes the ddebug_lock and
1070 * seeks the seq_file's iterator to the given position.
1072 static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
1074 struct ddebug_iter *iter = m->private;
1078 mutex_lock(&ddebug_lock);
1081 return SEQ_START_TOKEN;
1084 dp = ddebug_iter_first(iter);
1085 while (dp != NULL && --n > 0)
1086 dp = ddebug_iter_next(iter);
1091 * Seq_ops next method. Called several times within a read()
1092 * call from userspace, with ddebug_lock held. Walks to the
1093 * next _ddebug object with a special case for the header line.
1095 static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
1097 struct ddebug_iter *iter = m->private;
1100 if (p == SEQ_START_TOKEN)
1101 dp = ddebug_iter_first(iter);
1103 dp = ddebug_iter_next(iter);
1108 #define class_in_range(class_id, map) \
1109 (class_id >= map->base && class_id < map->base + map->length)
1111 static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
1113 struct ddebug_class_map *map;
1115 list_for_each_entry(map, &iter->table->maps, link)
1116 if (class_in_range(dp->class_id, map))
1117 return map->class_names[dp->class_id - map->base];
1123 * Seq_ops show method. Called several times within a read()
1124 * call from userspace, with ddebug_lock held. Formats the
1125 * current _ddebug as a single human-readable line, with a
1126 * special case for the header line.
1128 static int ddebug_proc_show(struct seq_file *m, void *p)
1130 struct ddebug_iter *iter = m->private;
1131 struct _ddebug *dp = p;
1132 struct flagsbuf flags;
1135 if (p == SEQ_START_TOKEN) {
1137 "# filename:lineno [module]function flags format\n");
1141 seq_printf(m, "%s:%u [%s]%s =%s \"",
1142 trim_prefix(dp->filename), dp->lineno,
1143 iter->table->mod_name, dp->function,
1144 ddebug_describe_flags(dp->flags, &flags));
1145 seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
1148 if (dp->class_id != _DPRINTK_CLASS_DFLT) {
1149 class = ddebug_class_name(iter, dp);
1151 seq_printf(m, " class:%s", class);
1153 seq_printf(m, " class unknown, _id:%d", dp->class_id);
1161 * Seq_ops stop method. Called at the end of each read()
1162 * call from userspace. Drops ddebug_lock.
1164 static void ddebug_proc_stop(struct seq_file *m, void *p)
1166 mutex_unlock(&ddebug_lock);
1169 static const struct seq_operations ddebug_proc_seqops = {
1170 .start = ddebug_proc_start,
1171 .next = ddebug_proc_next,
1172 .show = ddebug_proc_show,
1173 .stop = ddebug_proc_stop
1176 static int ddebug_proc_open(struct inode *inode, struct file *file)
1178 return seq_open_private(file, &ddebug_proc_seqops,
1179 sizeof(struct ddebug_iter));
1182 static const struct file_operations ddebug_proc_fops = {
1183 .owner = THIS_MODULE,
1184 .open = ddebug_proc_open,
1186 .llseek = seq_lseek,
1187 .release = seq_release_private,
1188 .write = ddebug_proc_write
1191 static const struct proc_ops proc_fops = {
1192 .proc_open = ddebug_proc_open,
1193 .proc_read = seq_read,
1194 .proc_lseek = seq_lseek,
1195 .proc_release = seq_release_private,
1196 .proc_write = ddebug_proc_write
1199 static void ddebug_attach_module_classes(struct ddebug_table *dt,
1200 struct ddebug_class_map *classes,
1203 struct ddebug_class_map *cm;
1206 for (cm = classes, i = 0; i < num_classes; i++, cm++) {
1208 if (!strcmp(cm->mod_name, dt->mod_name)) {
1210 v2pr_info("class[%d]: module:%s base:%d len:%d ty:%d\n", i,
1211 cm->mod_name, cm->base, cm->length, cm->map_type);
1213 for (j = 0; j < cm->length; j++)
1214 v3pr_info(" %d: %d %s\n", j + cm->base, j,
1215 cm->class_names[j]);
1217 list_add(&cm->link, &dt->maps);
1222 vpr_info("module:%s attached %d classes\n", dt->mod_name, ct);
1226 * Allocate a new ddebug_table for the given module
1227 * and add it to the global list.
1229 static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
1231 struct ddebug_table *dt;
1233 v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
1234 if (!di->num_descs) {
1235 v3pr_info(" skip %s\n", modname);
1239 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
1241 pr_err("error adding module: %s\n", modname);
1245 * For built-in modules, name lives in .rodata and is
1246 * immortal. For loaded modules, name points at the name[]
1247 * member of struct module, which lives at least as long as
1248 * this struct ddebug_table.
1250 dt->mod_name = modname;
1251 dt->ddebugs = di->descs;
1252 dt->num_ddebugs = di->num_descs;
1254 INIT_LIST_HEAD(&dt->link);
1255 INIT_LIST_HEAD(&dt->maps);
1257 if (di->classes && di->num_classes)
1258 ddebug_attach_module_classes(dt, di->classes, di->num_classes);
1260 mutex_lock(&ddebug_lock);
1261 list_add_tail(&dt->link, &ddebug_tables);
1262 mutex_unlock(&ddebug_lock);
1264 vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
1268 /* helper for ddebug_dyndbg_(boot|module)_param_cb */
1269 static int ddebug_dyndbg_param_cb(char *param, char *val,
1270 const char *modname, int on_err)
1274 sep = strchr(param, '.');
1276 /* needed only for ddebug_dyndbg_boot_param_cb */
1281 if (strcmp(param, "dyndbg"))
1282 return on_err; /* determined by caller */
1284 ddebug_exec_queries((val ? val : "+p"), modname);
1286 return 0; /* query failure shouldn't stop module load */
1289 /* handle both dyndbg and $module.dyndbg params at boot */
1290 static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
1291 const char *unused, void *arg)
1293 vpr_info("%s=\"%s\"\n", param, val);
1294 return ddebug_dyndbg_param_cb(param, val, NULL, 0);
1298 * modprobe foo finds foo.params in boot-args, strips "foo.", and
1299 * passes them to load_module(). This callback gets unknown params,
1300 * processes dyndbg params, rejects others.
1302 int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
1304 vpr_info("module: %s %s=\"%s\"\n", module, param, val);
1305 return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
1308 static void ddebug_table_free(struct ddebug_table *dt)
1310 list_del_init(&dt->link);
1314 #ifdef CONFIG_MODULES
1317 * Called in response to a module being unloaded. Removes
1318 * any ddebug_table's which point at the module.
1320 static int ddebug_remove_module(const char *mod_name)
1322 struct ddebug_table *dt, *nextdt;
1325 mutex_lock(&ddebug_lock);
1326 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
1327 if (dt->mod_name == mod_name) {
1328 ddebug_table_free(dt);
1333 mutex_unlock(&ddebug_lock);
1335 v2pr_info("removed module \"%s\"\n", mod_name);
1339 static int ddebug_module_notify(struct notifier_block *self, unsigned long val,
1342 struct module *mod = data;
1346 case MODULE_STATE_COMING:
1347 ret = ddebug_add_module(&mod->dyndbg_info, mod->name);
1349 WARN(1, "Failed to allocate memory: dyndbg may not work properly.\n");
1351 case MODULE_STATE_GOING:
1352 ddebug_remove_module(mod->name);
1356 return notifier_from_errno(ret);
1359 static struct notifier_block ddebug_module_nb = {
1360 .notifier_call = ddebug_module_notify,
1361 .priority = 0, /* dynamic debug depends on jump label */
1364 #endif /* CONFIG_MODULES */
1366 static void ddebug_remove_all_tables(void)
1368 mutex_lock(&ddebug_lock);
1369 while (!list_empty(&ddebug_tables)) {
1370 struct ddebug_table *dt = list_entry(ddebug_tables.next,
1371 struct ddebug_table,
1373 ddebug_table_free(dt);
1375 mutex_unlock(&ddebug_lock);
1378 static __initdata int ddebug_init_success;
1380 static int __init dynamic_debug_init_control(void)
1382 struct proc_dir_entry *procfs_dir;
1383 struct dentry *debugfs_dir;
1385 if (!ddebug_init_success)
1388 /* Create the control file in debugfs if it is enabled */
1389 if (debugfs_initialized()) {
1390 debugfs_dir = debugfs_create_dir("dynamic_debug", NULL);
1391 debugfs_create_file("control", 0644, debugfs_dir, NULL,
1395 /* Also create the control file in procfs */
1396 procfs_dir = proc_mkdir("dynamic_debug", NULL);
1398 proc_create("control", 0644, procfs_dir, &proc_fops);
1403 static int __init dynamic_debug_init(void)
1405 struct _ddebug *iter, *iter_mod_start;
1406 int ret, i, mod_sites, mod_ct;
1407 const char *modname;
1410 struct _ddebug_info di = {
1411 .descs = __start___dyndbg,
1412 .classes = __start___dyndbg_classes,
1413 .num_descs = __stop___dyndbg - __start___dyndbg,
1414 .num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
1417 #ifdef CONFIG_MODULES
1418 ret = register_module_notifier(&ddebug_module_nb);
1420 pr_warn("Failed to register dynamic debug module notifier\n");
1423 #endif /* CONFIG_MODULES */
1425 if (&__start___dyndbg == &__stop___dyndbg) {
1426 if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
1427 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1430 pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
1431 ddebug_init_success = 1;
1435 iter = iter_mod_start = __start___dyndbg;
1436 modname = iter->modname;
1437 i = mod_sites = mod_ct = 0;
1439 for (; iter < __stop___dyndbg; iter++, i++, mod_sites++) {
1441 if (strcmp(modname, iter->modname)) {
1443 di.num_descs = mod_sites;
1444 di.descs = iter_mod_start;
1445 ret = ddebug_add_module(&di, modname);
1450 modname = iter->modname;
1451 iter_mod_start = iter;
1454 di.num_descs = mod_sites;
1455 di.descs = iter_mod_start;
1456 ret = ddebug_add_module(&di, modname);
1460 ddebug_init_success = 1;
1461 vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg section\n",
1462 i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
1463 (int)((i * sizeof(struct _ddebug)) >> 10));
1466 v2pr_info(" %d builtin ddebug class-maps\n", di.num_classes);
1468 /* now that ddebug tables are loaded, process all boot args
1469 * again to find and activate queries given in dyndbg params.
1470 * While this has already been done for known boot params, it
1471 * ignored the unknown ones (dyndbg in particular). Reusing
1472 * parse_args avoids ad-hoc parsing. This will also attempt
1473 * to activate queries for not-yet-loaded modules, which is
1474 * slightly noisy if verbose, but harmless.
1476 cmdline = kstrdup(saved_command_line, GFP_KERNEL);
1477 parse_args("dyndbg params", cmdline, NULL,
1478 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
1483 ddebug_remove_all_tables();
1486 /* Allow early initialization for boot messages via boot param */
1487 early_initcall(dynamic_debug_init);
1489 /* Debugfs setup must be done later */
1490 fs_initcall(dynamic_debug_init_control);