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) KBUILD_MODNAME ":%s: " fmt, __func__
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___verbose
[];
43 extern struct _ddebug __stop___verbose
[];
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 static DEFINE_MUTEX(ddebug_lock
);
66 static LIST_HEAD(ddebug_tables
);
68 module_param(verbose
, int, 0644);
70 /* Return the path relative to source root */
71 static inline const char *trim_prefix(const char *path
)
73 int skip
= strlen(__FILE__
) - strlen("lib/dynamic_debug.c");
75 if (strncmp(path
, __FILE__
, skip
))
76 skip
= 0; /* prefix mismatch, don't skip */
81 static struct { unsigned flag
:8; char opt_char
; } opt_array
[] = {
82 { _DPRINTK_FLAGS_PRINT
, 'p' },
83 { _DPRINTK_FLAGS_INCL_MODNAME
, 'm' },
84 { _DPRINTK_FLAGS_INCL_FUNCNAME
, 'f' },
85 { _DPRINTK_FLAGS_INCL_LINENO
, 'l' },
86 { _DPRINTK_FLAGS_INCL_TID
, 't' },
87 { _DPRINTK_FLAGS_NONE
, '_' },
90 /* format a string into buf[] which describes the _ddebug's flags */
91 static char *ddebug_describe_flags(struct _ddebug
*dp
, char *buf
,
98 for (i
= 0; i
< ARRAY_SIZE(opt_array
); ++i
)
99 if (dp
->flags
& opt_array
[i
].flag
)
100 *p
++ = opt_array
[i
].opt_char
;
108 #define vpr_info(fmt, ...) \
111 pr_info(fmt, ##__VA_ARGS__); \
114 static void vpr_info_dq(const struct ddebug_query
*query
, const char *msg
)
116 /* trim any trailing newlines */
120 fmtlen
= strlen(query
->format
);
121 while (fmtlen
&& query
->format
[fmtlen
- 1] == '\n')
125 vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n",
127 query
->function
? query
->function
: "",
128 query
->filename
? query
->filename
: "",
129 query
->module
? query
->module
: "",
130 fmtlen
, query
->format
? query
->format
: "",
131 query
->first_lineno
, query
->last_lineno
);
135 * Search the tables for _ddebug's which match the given `query' and
136 * apply the `flags' and `mask' to them. Returns number of matching
137 * callsites, normally the same as number of changes. If verbose,
138 * logs the changes. Takes ddebug_lock.
140 static int ddebug_change(const struct ddebug_query
*query
,
141 unsigned int flags
, unsigned int mask
)
144 struct ddebug_table
*dt
;
145 unsigned int newflags
;
146 unsigned int nfound
= 0;
149 /* search for matching ddebugs */
150 mutex_lock(&ddebug_lock
);
151 list_for_each_entry(dt
, &ddebug_tables
, link
) {
153 /* match against the module name */
155 !match_wildcard(query
->module
, dt
->mod_name
))
158 for (i
= 0; i
< dt
->num_ddebugs
; i
++) {
159 struct _ddebug
*dp
= &dt
->ddebugs
[i
];
161 /* match against the source filename */
162 if (query
->filename
&&
163 !match_wildcard(query
->filename
, dp
->filename
) &&
164 !match_wildcard(query
->filename
,
165 kbasename(dp
->filename
)) &&
166 !match_wildcard(query
->filename
,
167 trim_prefix(dp
->filename
)))
170 /* match against the function */
171 if (query
->function
&&
172 !match_wildcard(query
->function
, dp
->function
))
175 /* match against the format */
177 !strstr(dp
->format
, query
->format
))
180 /* match against the line number range */
181 if (query
->first_lineno
&&
182 dp
->lineno
< query
->first_lineno
)
184 if (query
->last_lineno
&&
185 dp
->lineno
> query
->last_lineno
)
190 newflags
= (dp
->flags
& mask
) | flags
;
191 if (newflags
== dp
->flags
)
193 #ifdef CONFIG_JUMP_LABEL
194 if (dp
->flags
& _DPRINTK_FLAGS_PRINT
) {
195 if (!(flags
& _DPRINTK_FLAGS_PRINT
))
196 static_branch_disable(&dp
->key
.dd_key_true
);
197 } else if (flags
& _DPRINTK_FLAGS_PRINT
)
198 static_branch_enable(&dp
->key
.dd_key_true
);
200 dp
->flags
= newflags
;
201 vpr_info("changed %s:%d [%s]%s =%s\n",
202 trim_prefix(dp
->filename
), dp
->lineno
,
203 dt
->mod_name
, dp
->function
,
204 ddebug_describe_flags(dp
, flagbuf
,
208 mutex_unlock(&ddebug_lock
);
210 if (!nfound
&& verbose
)
211 pr_info("no matches for query\n");
217 * Split the buffer `buf' into space-separated words.
218 * Handles simple " and ' quoting, i.e. without nested,
219 * embedded or escaped \". Return the number of words
222 static int ddebug_tokenize(char *buf
, char *words
[], int maxwords
)
229 /* Skip leading whitespace */
230 buf
= skip_spaces(buf
);
232 break; /* oh, it was trailing whitespace */
234 break; /* token starts comment, skip rest of line */
236 /* find `end' of word, whitespace separated or quoted */
237 if (*buf
== '"' || *buf
== '\'') {
239 for (end
= buf
; *end
&& *end
!= quote
; end
++)
242 pr_err("unclosed quote: %s\n", buf
);
243 return -EINVAL
; /* unclosed quote */
246 for (end
= buf
; *end
&& !isspace(*end
); end
++)
251 /* `buf' is start of word, `end' is one past its end */
252 if (nwords
== maxwords
) {
253 pr_err("too many words, legal max <=%d\n", maxwords
);
254 return -EINVAL
; /* ran out of words[] before bytes */
257 *end
++ = '\0'; /* terminate the word */
258 words
[nwords
++] = buf
;
264 pr_info("split into words:");
265 for (i
= 0; i
< nwords
; i
++)
266 pr_cont(" \"%s\"", words
[i
]);
274 * Parse a single line number. Note that the empty string ""
275 * is treated as a special case and converted to zero, which
276 * is later treated as a "don't care" value.
278 static inline int parse_lineno(const char *str
, unsigned int *val
)
285 if (kstrtouint(str
, 10, val
) < 0) {
286 pr_err("bad line-number: %s\n", str
);
292 static int check_set(const char **dest
, char *src
, char *name
)
298 pr_err("match-spec:%s val:%s overridden by %s\n",
306 * Parse words[] as a ddebug query specification, which is a series
307 * of (keyword, value) pairs chosen from these possibilities:
309 * func <function-name>
310 * file <full-pathname>
311 * file <base-filename>
312 * module <module-name>
313 * format <escaped-string-to-find-in-format>
315 * line <first-lineno>-<last-lineno> // where either may be empty
317 * Only 1 of each type is allowed.
318 * Returns 0 on success, <0 on error.
320 static int ddebug_parse_query(char *words
[], int nwords
,
321 struct ddebug_query
*query
, const char *modname
)
326 /* check we have an even number of words */
327 if (nwords
% 2 != 0) {
328 pr_err("expecting pairs of match-spec <value>\n");
331 memset(query
, 0, sizeof(*query
));
334 /* support $modname.dyndbg=<multiple queries> */
335 query
->module
= modname
;
337 for (i
= 0; i
< nwords
; i
+= 2) {
338 if (!strcmp(words
[i
], "func")) {
339 rc
= check_set(&query
->function
, words
[i
+1], "func");
340 } else if (!strcmp(words
[i
], "file")) {
341 rc
= check_set(&query
->filename
, words
[i
+1], "file");
342 } else if (!strcmp(words
[i
], "module")) {
343 rc
= check_set(&query
->module
, words
[i
+1], "module");
344 } else if (!strcmp(words
[i
], "format")) {
345 string_unescape_inplace(words
[i
+1], UNESCAPE_SPACE
|
348 rc
= check_set(&query
->format
, words
[i
+1], "format");
349 } else if (!strcmp(words
[i
], "line")) {
350 char *first
= words
[i
+1];
351 char *last
= strchr(first
, '-');
352 if (query
->first_lineno
|| query
->last_lineno
) {
353 pr_err("match-spec: line used 2x\n");
358 if (parse_lineno(first
, &query
->first_lineno
) < 0)
361 /* range <first>-<last> */
362 if (parse_lineno(last
, &query
->last_lineno
) < 0)
365 /* special case for last lineno not specified */
366 if (query
->last_lineno
== 0)
367 query
->last_lineno
= UINT_MAX
;
369 if (query
->last_lineno
< query
->first_lineno
) {
370 pr_err("last-line:%d < 1st-line:%d\n",
372 query
->first_lineno
);
376 query
->last_lineno
= query
->first_lineno
;
379 pr_err("unknown keyword \"%s\"\n", words
[i
]);
385 vpr_info_dq(query
, "parsed");
390 * Parse `str' as a flags specification, format [-+=][p]+.
391 * Sets up *maskp and *flagsp to be used when changing the
392 * flags fields of matched _ddebug's. Returns 0 on success
395 static int ddebug_parse_flags(const char *str
, unsigned int *flagsp
,
408 pr_err("bad flag-op %c, at start of %s\n", *str
, str
);
411 vpr_info("op='%c'\n", op
);
413 for (; *str
; ++str
) {
414 for (i
= ARRAY_SIZE(opt_array
) - 1; i
>= 0; i
--) {
415 if (*str
== opt_array
[i
].opt_char
) {
416 flags
|= opt_array
[i
].flag
;
421 pr_err("unknown flag '%c' in \"%s\"\n", *str
, str
);
425 vpr_info("flags=0x%x\n", flags
);
427 /* calculate final *flagsp, *maskp according to mask and op */
442 vpr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp
, *maskp
);
446 static int ddebug_exec_query(char *query_string
, const char *modname
)
448 unsigned int flags
= 0, mask
= 0;
449 struct ddebug_query query
;
452 char *words
[MAXWORDS
];
454 nwords
= ddebug_tokenize(query_string
, words
, MAXWORDS
);
456 pr_err("tokenize failed\n");
459 /* check flags 1st (last arg) so query is pairs of spec,val */
460 if (ddebug_parse_flags(words
[nwords
-1], &flags
, &mask
)) {
461 pr_err("flags parse failed\n");
464 if (ddebug_parse_query(words
, nwords
-1, &query
, modname
)) {
465 pr_err("query parse failed\n");
468 /* actually go and implement the change */
469 nfound
= ddebug_change(&query
, flags
, mask
);
470 vpr_info_dq(&query
, nfound
? "applied" : "no-match");
475 /* handle multiple queries in query string, continue on error, return
476 last error or number of matching callsites. Module name is either
477 in param (for boot arg) or perhaps in query string.
479 static int ddebug_exec_queries(char *query
, const char *modname
)
482 int i
, errs
= 0, exitcode
= 0, rc
, nfound
= 0;
484 for (i
= 0; query
; query
= split
) {
485 split
= strpbrk(query
, ";\n");
489 query
= skip_spaces(query
);
490 if (!query
|| !*query
|| *query
== '#')
493 vpr_info("query %d: \"%s\"\n", i
, query
);
495 rc
= ddebug_exec_query(query
, modname
);
504 vpr_info("processed %d queries, with %d matches, %d errs\n",
512 #define PREFIX_SIZE 64
514 static int remaining(int wrote
)
516 if (PREFIX_SIZE
- wrote
> 0)
517 return PREFIX_SIZE
- wrote
;
521 static char *dynamic_emit_prefix(const struct _ddebug
*desc
, char *buf
)
528 if (desc
->flags
& _DPRINTK_FLAGS_INCL_TID
) {
530 pos
+= snprintf(buf
+ pos
, remaining(pos
), "<intr> ");
532 pos
+= snprintf(buf
+ pos
, remaining(pos
), "[%d] ",
533 task_pid_vnr(current
));
536 if (desc
->flags
& _DPRINTK_FLAGS_INCL_MODNAME
)
537 pos
+= snprintf(buf
+ pos
, remaining(pos
), "%s:",
539 if (desc
->flags
& _DPRINTK_FLAGS_INCL_FUNCNAME
)
540 pos
+= snprintf(buf
+ pos
, remaining(pos
), "%s:",
542 if (desc
->flags
& _DPRINTK_FLAGS_INCL_LINENO
)
543 pos
+= snprintf(buf
+ pos
, remaining(pos
), "%d:",
545 if (pos
- pos_after_tid
)
546 pos
+= snprintf(buf
+ pos
, remaining(pos
), " ");
547 if (pos
>= PREFIX_SIZE
)
548 buf
[PREFIX_SIZE
- 1] = '\0';
553 void __dynamic_pr_debug(struct _ddebug
*descriptor
, const char *fmt
, ...)
556 struct va_format vaf
;
557 char buf
[PREFIX_SIZE
];
567 printk(KERN_DEBUG
"%s%pV", dynamic_emit_prefix(descriptor
, buf
), &vaf
);
571 EXPORT_SYMBOL(__dynamic_pr_debug
);
573 void __dynamic_dev_dbg(struct _ddebug
*descriptor
,
574 const struct device
*dev
, const char *fmt
, ...)
576 struct va_format vaf
;
588 printk(KERN_DEBUG
"(NULL device *): %pV", &vaf
);
590 char buf
[PREFIX_SIZE
];
592 dev_printk_emit(LOGLEVEL_DEBUG
, dev
, "%s%s %s: %pV",
593 dynamic_emit_prefix(descriptor
, buf
),
594 dev_driver_string(dev
), dev_name(dev
),
600 EXPORT_SYMBOL(__dynamic_dev_dbg
);
604 void __dynamic_netdev_dbg(struct _ddebug
*descriptor
,
605 const struct net_device
*dev
, const char *fmt
, ...)
607 struct va_format vaf
;
618 if (dev
&& dev
->dev
.parent
) {
619 char buf
[PREFIX_SIZE
];
621 dev_printk_emit(LOGLEVEL_DEBUG
, dev
->dev
.parent
,
623 dynamic_emit_prefix(descriptor
, buf
),
624 dev_driver_string(dev
->dev
.parent
),
625 dev_name(dev
->dev
.parent
),
626 netdev_name(dev
), netdev_reg_state(dev
),
629 printk(KERN_DEBUG
"%s%s: %pV", netdev_name(dev
),
630 netdev_reg_state(dev
), &vaf
);
632 printk(KERN_DEBUG
"(NULL net_device): %pV", &vaf
);
637 EXPORT_SYMBOL(__dynamic_netdev_dbg
);
641 #if IS_ENABLED(CONFIG_INFINIBAND)
643 void __dynamic_ibdev_dbg(struct _ddebug
*descriptor
,
644 const struct ib_device
*ibdev
, const char *fmt
, ...)
646 struct va_format vaf
;
654 if (ibdev
&& ibdev
->dev
.parent
) {
655 char buf
[PREFIX_SIZE
];
657 dev_printk_emit(LOGLEVEL_DEBUG
, ibdev
->dev
.parent
,
659 dynamic_emit_prefix(descriptor
, buf
),
660 dev_driver_string(ibdev
->dev
.parent
),
661 dev_name(ibdev
->dev
.parent
),
662 dev_name(&ibdev
->dev
),
665 printk(KERN_DEBUG
"%s: %pV", dev_name(&ibdev
->dev
), &vaf
);
667 printk(KERN_DEBUG
"(NULL ib_device): %pV", &vaf
);
672 EXPORT_SYMBOL(__dynamic_ibdev_dbg
);
676 #define DDEBUG_STRING_SIZE 1024
677 static __initdata
char ddebug_setup_string
[DDEBUG_STRING_SIZE
];
679 static __init
int ddebug_setup_query(char *str
)
681 if (strlen(str
) >= DDEBUG_STRING_SIZE
) {
682 pr_warn("ddebug boot param string too large\n");
685 strlcpy(ddebug_setup_string
, str
, DDEBUG_STRING_SIZE
);
689 __setup("ddebug_query=", ddebug_setup_query
);
692 * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
693 * command text from userspace, parses and executes it.
695 #define USER_BUF_PAGE 4096
696 static ssize_t
ddebug_proc_write(struct file
*file
, const char __user
*ubuf
,
697 size_t len
, loff_t
*offp
)
704 if (len
> USER_BUF_PAGE
- 1) {
705 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE
);
708 tmpbuf
= memdup_user_nul(ubuf
, len
);
710 return PTR_ERR(tmpbuf
);
711 vpr_info("read %d bytes from userspace\n", (int)len
);
713 ret
= ddebug_exec_queries(tmpbuf
, NULL
);
723 * Set the iterator to point to the first _ddebug object
724 * and return a pointer to that first object. Returns
725 * NULL if there are no _ddebugs at all.
727 static struct _ddebug
*ddebug_iter_first(struct ddebug_iter
*iter
)
729 if (list_empty(&ddebug_tables
)) {
734 iter
->table
= list_entry(ddebug_tables
.next
,
735 struct ddebug_table
, link
);
737 return &iter
->table
->ddebugs
[iter
->idx
];
741 * Advance the iterator to point to the next _ddebug
742 * object from the one the iterator currently points at,
743 * and returns a pointer to the new _ddebug. Returns
744 * NULL if the iterator has seen all the _ddebugs.
746 static struct _ddebug
*ddebug_iter_next(struct ddebug_iter
*iter
)
748 if (iter
->table
== NULL
)
750 if (++iter
->idx
== iter
->table
->num_ddebugs
) {
751 /* iterate to next table */
753 if (list_is_last(&iter
->table
->link
, &ddebug_tables
)) {
757 iter
->table
= list_entry(iter
->table
->link
.next
,
758 struct ddebug_table
, link
);
760 return &iter
->table
->ddebugs
[iter
->idx
];
764 * Seq_ops start method. Called at the start of every
765 * read() call from userspace. Takes the ddebug_lock and
766 * seeks the seq_file's iterator to the given position.
768 static void *ddebug_proc_start(struct seq_file
*m
, loff_t
*pos
)
770 struct ddebug_iter
*iter
= m
->private;
774 vpr_info("called m=%p *pos=%lld\n", m
, (unsigned long long)*pos
);
776 mutex_lock(&ddebug_lock
);
779 return SEQ_START_TOKEN
;
782 dp
= ddebug_iter_first(iter
);
783 while (dp
!= NULL
&& --n
> 0)
784 dp
= ddebug_iter_next(iter
);
789 * Seq_ops next method. Called several times within a read()
790 * call from userspace, with ddebug_lock held. Walks to the
791 * next _ddebug object with a special case for the header line.
793 static void *ddebug_proc_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
795 struct ddebug_iter
*iter
= m
->private;
798 vpr_info("called m=%p p=%p *pos=%lld\n",
799 m
, p
, (unsigned long long)*pos
);
801 if (p
== SEQ_START_TOKEN
)
802 dp
= ddebug_iter_first(iter
);
804 dp
= ddebug_iter_next(iter
);
810 * Seq_ops show method. Called several times within a read()
811 * call from userspace, with ddebug_lock held. Formats the
812 * current _ddebug as a single human-readable line, with a
813 * special case for the header line.
815 static int ddebug_proc_show(struct seq_file
*m
, void *p
)
817 struct ddebug_iter
*iter
= m
->private;
818 struct _ddebug
*dp
= p
;
821 vpr_info("called m=%p p=%p\n", m
, p
);
823 if (p
== SEQ_START_TOKEN
) {
825 "# filename:lineno [module]function flags format\n");
829 seq_printf(m
, "%s:%u [%s]%s =%s \"",
830 trim_prefix(dp
->filename
), dp
->lineno
,
831 iter
->table
->mod_name
, dp
->function
,
832 ddebug_describe_flags(dp
, flagsbuf
, sizeof(flagsbuf
)));
833 seq_escape(m
, dp
->format
, "\t\r\n\"");
840 * Seq_ops stop method. Called at the end of each read()
841 * call from userspace. Drops ddebug_lock.
843 static void ddebug_proc_stop(struct seq_file
*m
, void *p
)
845 vpr_info("called m=%p p=%p\n", m
, p
);
846 mutex_unlock(&ddebug_lock
);
849 static const struct seq_operations ddebug_proc_seqops
= {
850 .start
= ddebug_proc_start
,
851 .next
= ddebug_proc_next
,
852 .show
= ddebug_proc_show
,
853 .stop
= ddebug_proc_stop
857 * File_ops->open method for <debugfs>/dynamic_debug/control. Does
858 * the seq_file setup dance, and also creates an iterator to walk the
859 * _ddebugs. Note that we create a seq_file always, even for O_WRONLY
860 * files where it's not needed, as doing so simplifies the ->release
863 static int ddebug_proc_open(struct inode
*inode
, struct file
*file
)
865 vpr_info("called\n");
866 return seq_open_private(file
, &ddebug_proc_seqops
,
867 sizeof(struct ddebug_iter
));
870 static const struct file_operations ddebug_proc_fops
= {
871 .owner
= THIS_MODULE
,
872 .open
= ddebug_proc_open
,
875 .release
= seq_release_private
,
876 .write
= ddebug_proc_write
879 static const struct proc_ops proc_fops
= {
880 .proc_open
= ddebug_proc_open
,
881 .proc_read
= seq_read
,
882 .proc_lseek
= seq_lseek
,
883 .proc_release
= seq_release_private
,
884 .proc_write
= ddebug_proc_write
888 * Allocate a new ddebug_table for the given module
889 * and add it to the global list.
891 int ddebug_add_module(struct _ddebug
*tab
, unsigned int n
,
894 struct ddebug_table
*dt
;
896 dt
= kzalloc(sizeof(*dt
), GFP_KERNEL
);
898 pr_err("error adding module: %s\n", name
);
902 * For built-in modules, name lives in .rodata and is
903 * immortal. For loaded modules, name points at the name[]
904 * member of struct module, which lives at least as long as
905 * this struct ddebug_table.
911 mutex_lock(&ddebug_lock
);
912 list_add_tail(&dt
->link
, &ddebug_tables
);
913 mutex_unlock(&ddebug_lock
);
915 vpr_info("%u debug prints in module %s\n", n
, dt
->mod_name
);
919 /* helper for ddebug_dyndbg_(boot|module)_param_cb */
920 static int ddebug_dyndbg_param_cb(char *param
, char *val
,
921 const char *modname
, int on_err
)
925 sep
= strchr(param
, '.');
927 /* needed only for ddebug_dyndbg_boot_param_cb */
932 if (strcmp(param
, "dyndbg"))
933 return on_err
; /* determined by caller */
935 ddebug_exec_queries((val
? val
: "+p"), modname
);
937 return 0; /* query failure shouldnt stop module load */
940 /* handle both dyndbg and $module.dyndbg params at boot */
941 static int ddebug_dyndbg_boot_param_cb(char *param
, char *val
,
942 const char *unused
, void *arg
)
944 vpr_info("%s=\"%s\"\n", param
, val
);
945 return ddebug_dyndbg_param_cb(param
, val
, NULL
, 0);
949 * modprobe foo finds foo.params in boot-args, strips "foo.", and
950 * passes them to load_module(). This callback gets unknown params,
951 * processes dyndbg params, rejects others.
953 int ddebug_dyndbg_module_param_cb(char *param
, char *val
, const char *module
)
955 vpr_info("module: %s %s=\"%s\"\n", module
, param
, val
);
956 return ddebug_dyndbg_param_cb(param
, val
, module
, -ENOENT
);
959 static void ddebug_table_free(struct ddebug_table
*dt
)
961 list_del_init(&dt
->link
);
966 * Called in response to a module being unloaded. Removes
967 * any ddebug_table's which point at the module.
969 int ddebug_remove_module(const char *mod_name
)
971 struct ddebug_table
*dt
, *nextdt
;
974 vpr_info("removing module \"%s\"\n", mod_name
);
976 mutex_lock(&ddebug_lock
);
977 list_for_each_entry_safe(dt
, nextdt
, &ddebug_tables
, link
) {
978 if (dt
->mod_name
== mod_name
) {
979 ddebug_table_free(dt
);
984 mutex_unlock(&ddebug_lock
);
988 static void ddebug_remove_all_tables(void)
990 mutex_lock(&ddebug_lock
);
991 while (!list_empty(&ddebug_tables
)) {
992 struct ddebug_table
*dt
= list_entry(ddebug_tables
.next
,
995 ddebug_table_free(dt
);
997 mutex_unlock(&ddebug_lock
);
1000 static __initdata
int ddebug_init_success
;
1002 static int __init
dynamic_debug_init_control(void)
1004 struct proc_dir_entry
*procfs_dir
;
1005 struct dentry
*debugfs_dir
;
1007 if (!ddebug_init_success
)
1010 /* Create the control file in debugfs if it is enabled */
1011 if (debugfs_initialized()) {
1012 debugfs_dir
= debugfs_create_dir("dynamic_debug", NULL
);
1013 debugfs_create_file("control", 0644, debugfs_dir
, NULL
,
1017 /* Also create the control file in procfs */
1018 procfs_dir
= proc_mkdir("dynamic_debug", NULL
);
1020 proc_create("control", 0644, procfs_dir
, &proc_fops
);
1025 static int __init
dynamic_debug_init(void)
1027 struct _ddebug
*iter
, *iter_start
;
1028 const char *modname
= NULL
;
1031 int n
= 0, entries
= 0, modct
= 0;
1032 int verbose_bytes
= 0;
1034 if (&__start___verbose
== &__stop___verbose
) {
1035 if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG
)) {
1036 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
1039 pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
1040 ddebug_init_success
= 1;
1043 iter
= __start___verbose
;
1044 modname
= iter
->modname
;
1046 for (; iter
< __stop___verbose
; iter
++) {
1048 verbose_bytes
+= strlen(iter
->modname
) + strlen(iter
->function
)
1049 + strlen(iter
->filename
) + strlen(iter
->format
);
1051 if (strcmp(modname
, iter
->modname
)) {
1053 ret
= ddebug_add_module(iter_start
, n
, modname
);
1057 modname
= iter
->modname
;
1062 ret
= ddebug_add_module(iter_start
, n
, modname
);
1066 ddebug_init_success
= 1;
1067 vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in (readonly) verbose section\n",
1068 modct
, entries
, (int)(modct
* sizeof(struct ddebug_table
)),
1069 verbose_bytes
+ (int)(__stop___verbose
- __start___verbose
));
1071 /* apply ddebug_query boot param, dont unload tables on err */
1072 if (ddebug_setup_string
[0] != '\0') {
1073 pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n");
1074 ret
= ddebug_exec_queries(ddebug_setup_string
, NULL
);
1076 pr_warn("Invalid ddebug boot param %s\n",
1077 ddebug_setup_string
);
1079 pr_info("%d changes by ddebug_query\n", ret
);
1081 /* now that ddebug tables are loaded, process all boot args
1082 * again to find and activate queries given in dyndbg params.
1083 * While this has already been done for known boot params, it
1084 * ignored the unknown ones (dyndbg in particular). Reusing
1085 * parse_args avoids ad-hoc parsing. This will also attempt
1086 * to activate queries for not-yet-loaded modules, which is
1087 * slightly noisy if verbose, but harmless.
1089 cmdline
= kstrdup(saved_command_line
, GFP_KERNEL
);
1090 parse_args("dyndbg params", cmdline
, NULL
,
1091 0, 0, 0, NULL
, &ddebug_dyndbg_boot_param_cb
);
1096 ddebug_remove_all_tables();
1099 /* Allow early initialization for boot messages via boot param */
1100 early_initcall(dynamic_debug_init
);
1102 /* Debugfs setup must be done later */
1103 fs_initcall(dynamic_debug_init_control
);