blob: a5508a12b83d09724831ad754cc279cd3b79cfd6 [file] [log] [blame]
Jason Barone9d376f2009-02-05 11:51:38 -05001/*
2 * lib/dynamic_debug.c
3 *
4 * make pr_debug()/dev_dbg() calls runtime configurable based upon their
5 * source module.
6 *
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.
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010010 * Copyright (C) 2011 Bart Van Assche. All Rights Reserved.
Jason Barone9d376f2009-02-05 11:51:38 -050011 */
12
Joe Perches4ad275e2011-08-11 14:36:33 -040013#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
14
Jason Barone9d376f2009-02-05 11:51:38 -050015#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/moduleparam.h>
18#include <linux/kallsyms.h>
Jason Barone9d376f2009-02-05 11:51:38 -050019#include <linux/types.h>
20#include <linux/mutex.h>
21#include <linux/proc_fs.h>
22#include <linux/seq_file.h>
23#include <linux/list.h>
24#include <linux/sysctl.h>
25#include <linux/ctype.h>
André Goddard Rosae7d28602009-12-14 18:01:06 -080026#include <linux/string.h>
Jason Barone9d376f2009-02-05 11:51:38 -050027#include <linux/uaccess.h>
28#include <linux/dynamic_debug.h>
29#include <linux/debugfs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090030#include <linux/slab.h>
Jason Baron52159d92010-09-17 11:09:17 -040031#include <linux/jump_label.h>
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010032#include <linux/hardirq.h>
Greg Kroah-Hartmane8d97922011-02-03 15:59:58 -080033#include <linux/sched.h>
Joe Perchescbc46632011-08-11 14:36:21 -040034#include <linux/device.h>
Jason Baronffa10cb2011-08-11 14:36:48 -040035#include <linux/netdevice.h>
Jason Barone9d376f2009-02-05 11:51:38 -050036
37extern struct _ddebug __start___verbose[];
38extern struct _ddebug __stop___verbose[];
39
Jason Barone9d376f2009-02-05 11:51:38 -050040struct ddebug_table {
41 struct list_head link;
42 char *mod_name;
43 unsigned int num_ddebugs;
Jason Barone9d376f2009-02-05 11:51:38 -050044 struct _ddebug *ddebugs;
45};
46
47struct ddebug_query {
48 const char *filename;
49 const char *module;
50 const char *function;
51 const char *format;
52 unsigned int first_lineno, last_lineno;
53};
54
55struct ddebug_iter {
56 struct ddebug_table *table;
57 unsigned int idx;
58};
59
60static DEFINE_MUTEX(ddebug_lock);
61static LIST_HEAD(ddebug_tables);
62static int verbose = 0;
Jim Cromie74df1382011-12-19 17:12:24 -050063module_param(verbose, int, 0644);
Jason Barone9d376f2009-02-05 11:51:38 -050064
65/* Return the last part of a pathname */
66static inline const char *basename(const char *path)
67{
68 const char *tail = strrchr(path, '/');
69 return tail ? tail+1 : path;
70}
71
Jim Cromie2b678312011-12-19 17:13:12 -050072/* Return the path relative to source root */
73static inline const char *trim_prefix(const char *path)
74{
75 int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
76
77 if (strncmp(path, __FILE__, skip))
78 skip = 0; /* prefix mismatch, don't skip */
79
80 return path + skip;
81}
82
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010083static struct { unsigned flag:8; char opt_char; } opt_array[] = {
84 { _DPRINTK_FLAGS_PRINT, 'p' },
85 { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
86 { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
87 { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
88 { _DPRINTK_FLAGS_INCL_TID, 't' },
Jim Cromie5ca7d2a2011-12-19 17:12:44 -050089 { _DPRINTK_FLAGS_NONE, '_' },
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010090};
91
Jason Barone9d376f2009-02-05 11:51:38 -050092/* format a string into buf[] which describes the _ddebug's flags */
93static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
94 size_t maxlen)
95{
96 char *p = buf;
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010097 int i;
Jason Barone9d376f2009-02-05 11:51:38 -050098
Jim Cromie5ca7d2a2011-12-19 17:12:44 -050099 BUG_ON(maxlen < 6);
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100100 for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
101 if (dp->flags & opt_array[i].flag)
102 *p++ = opt_array[i].opt_char;
Jason Barone9d376f2009-02-05 11:51:38 -0500103 if (p == buf)
Jim Cromie5ca7d2a2011-12-19 17:12:44 -0500104 *p++ = '_';
Jason Barone9d376f2009-02-05 11:51:38 -0500105 *p = '\0';
106
107 return buf;
108}
109
110/*
Jason Barone9d376f2009-02-05 11:51:38 -0500111 * Search the tables for _ddebug's which match the given
112 * `query' and apply the `flags' and `mask' to them. Tells
113 * the user which ddebug's were changed, or whether none
114 * were matched.
115 */
116static void ddebug_change(const struct ddebug_query *query,
117 unsigned int flags, unsigned int mask)
118{
119 int i;
120 struct ddebug_table *dt;
121 unsigned int newflags;
122 unsigned int nfound = 0;
Jim Cromie5ca7d2a2011-12-19 17:12:44 -0500123 char flagbuf[10];
Jason Barone9d376f2009-02-05 11:51:38 -0500124
125 /* search for matching ddebugs */
126 mutex_lock(&ddebug_lock);
127 list_for_each_entry(dt, &ddebug_tables, link) {
128
129 /* match against the module name */
Jim Cromied6a238d2011-12-19 17:12:39 -0500130 if (query->module && strcmp(query->module, dt->mod_name))
Jason Barone9d376f2009-02-05 11:51:38 -0500131 continue;
132
133 for (i = 0 ; i < dt->num_ddebugs ; i++) {
134 struct _ddebug *dp = &dt->ddebugs[i];
135
136 /* match against the source filename */
Jim Cromied6a238d2011-12-19 17:12:39 -0500137 if (query->filename &&
Jason Barone9d376f2009-02-05 11:51:38 -0500138 strcmp(query->filename, dp->filename) &&
Jim Cromie2b678312011-12-19 17:13:12 -0500139 strcmp(query->filename, basename(dp->filename)) &&
140 strcmp(query->filename, trim_prefix(dp->filename)))
Jason Barone9d376f2009-02-05 11:51:38 -0500141 continue;
142
143 /* match against the function */
Jim Cromied6a238d2011-12-19 17:12:39 -0500144 if (query->function &&
Jason Barone9d376f2009-02-05 11:51:38 -0500145 strcmp(query->function, dp->function))
146 continue;
147
148 /* match against the format */
Jim Cromied6a238d2011-12-19 17:12:39 -0500149 if (query->format &&
150 !strstr(dp->format, query->format))
Jason Barone9d376f2009-02-05 11:51:38 -0500151 continue;
152
153 /* match against the line number range */
154 if (query->first_lineno &&
155 dp->lineno < query->first_lineno)
156 continue;
157 if (query->last_lineno &&
158 dp->lineno > query->last_lineno)
159 continue;
160
161 nfound++;
162
163 newflags = (dp->flags & mask) | flags;
164 if (newflags == dp->flags)
165 continue;
Jason Barone9d376f2009-02-05 11:51:38 -0500166 dp->flags = newflags;
Jason Barone9d376f2009-02-05 11:51:38 -0500167 if (verbose)
Jim Cromie5ca7d2a2011-12-19 17:12:44 -0500168 pr_info("changed %s:%d [%s]%s =%s\n",
Jim Cromie2b678312011-12-19 17:13:12 -0500169 trim_prefix(dp->filename), dp->lineno,
Jason Barone9d376f2009-02-05 11:51:38 -0500170 dt->mod_name, dp->function,
171 ddebug_describe_flags(dp, flagbuf,
172 sizeof(flagbuf)));
173 }
174 }
175 mutex_unlock(&ddebug_lock);
176
177 if (!nfound && verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400178 pr_info("no matches for query\n");
Jason Barone9d376f2009-02-05 11:51:38 -0500179}
180
181/*
Jason Barone9d376f2009-02-05 11:51:38 -0500182 * Split the buffer `buf' into space-separated words.
Greg Banks9898abb2009-02-06 12:54:26 +1100183 * Handles simple " and ' quoting, i.e. without nested,
184 * embedded or escaped \". Return the number of words
185 * or <0 on error.
Jason Barone9d376f2009-02-05 11:51:38 -0500186 */
187static int ddebug_tokenize(char *buf, char *words[], int maxwords)
188{
189 int nwords = 0;
190
Greg Banks9898abb2009-02-06 12:54:26 +1100191 while (*buf) {
192 char *end;
193
194 /* Skip leading whitespace */
André Goddard Rosae7d28602009-12-14 18:01:06 -0800195 buf = skip_spaces(buf);
Greg Banks9898abb2009-02-06 12:54:26 +1100196 if (!*buf)
197 break; /* oh, it was trailing whitespace */
Jim Cromie8bd60262011-12-19 17:13:03 -0500198 if (*buf == '#')
199 break; /* token starts comment, skip rest of line */
Greg Banks9898abb2009-02-06 12:54:26 +1100200
Jim Cromie07100be2011-12-19 17:11:09 -0500201 /* find `end' of word, whitespace separated or quoted */
Greg Banks9898abb2009-02-06 12:54:26 +1100202 if (*buf == '"' || *buf == '\'') {
203 int quote = *buf++;
204 for (end = buf ; *end && *end != quote ; end++)
205 ;
206 if (!*end)
207 return -EINVAL; /* unclosed quote */
208 } else {
209 for (end = buf ; *end && !isspace(*end) ; end++)
210 ;
211 BUG_ON(end == buf);
212 }
Greg Banks9898abb2009-02-06 12:54:26 +1100213
Jim Cromie07100be2011-12-19 17:11:09 -0500214 /* `buf' is start of word, `end' is one past its end */
Greg Banks9898abb2009-02-06 12:54:26 +1100215 if (nwords == maxwords)
216 return -EINVAL; /* ran out of words[] before bytes */
217 if (*end)
218 *end++ = '\0'; /* terminate the word */
219 words[nwords++] = buf;
220 buf = end;
221 }
Jason Barone9d376f2009-02-05 11:51:38 -0500222
223 if (verbose) {
224 int i;
Joe Perches4ad275e2011-08-11 14:36:33 -0400225 pr_info("split into words:");
Jason Barone9d376f2009-02-05 11:51:38 -0500226 for (i = 0 ; i < nwords ; i++)
Joe Perches4ad275e2011-08-11 14:36:33 -0400227 pr_cont(" \"%s\"", words[i]);
228 pr_cont("\n");
Jason Barone9d376f2009-02-05 11:51:38 -0500229 }
230
231 return nwords;
232}
233
234/*
235 * Parse a single line number. Note that the empty string ""
236 * is treated as a special case and converted to zero, which
237 * is later treated as a "don't care" value.
238 */
239static inline int parse_lineno(const char *str, unsigned int *val)
240{
241 char *end = NULL;
242 BUG_ON(str == NULL);
243 if (*str == '\0') {
244 *val = 0;
245 return 0;
246 }
247 *val = simple_strtoul(str, &end, 10);
248 return end == NULL || end == str || *end != '\0' ? -EINVAL : 0;
249}
250
251/*
252 * Undo octal escaping in a string, inplace. This is useful to
253 * allow the user to express a query which matches a format
254 * containing embedded spaces.
255 */
256#define isodigit(c) ((c) >= '0' && (c) <= '7')
257static char *unescape(char *str)
258{
259 char *in = str;
260 char *out = str;
261
262 while (*in) {
263 if (*in == '\\') {
264 if (in[1] == '\\') {
265 *out++ = '\\';
266 in += 2;
267 continue;
268 } else if (in[1] == 't') {
269 *out++ = '\t';
270 in += 2;
271 continue;
272 } else if (in[1] == 'n') {
273 *out++ = '\n';
274 in += 2;
275 continue;
276 } else if (isodigit(in[1]) &&
277 isodigit(in[2]) &&
278 isodigit(in[3])) {
279 *out++ = ((in[1] - '0')<<6) |
280 ((in[2] - '0')<<3) |
281 (in[3] - '0');
282 in += 4;
283 continue;
284 }
285 }
286 *out++ = *in++;
287 }
288 *out = '\0';
289
290 return str;
291}
292
Jim Cromie820874c2011-12-19 17:12:49 -0500293static int check_set(const char **dest, char *src, char *name)
294{
295 int rc = 0;
296
297 if (*dest) {
298 rc = -EINVAL;
299 pr_err("match-spec:%s val:%s overridden by %s",
300 name, *dest, src);
301 }
302 *dest = src;
303 return rc;
304}
305
Jason Barone9d376f2009-02-05 11:51:38 -0500306/*
307 * Parse words[] as a ddebug query specification, which is a series
308 * of (keyword, value) pairs chosen from these possibilities:
309 *
310 * func <function-name>
311 * file <full-pathname>
312 * file <base-filename>
313 * module <module-name>
314 * format <escaped-string-to-find-in-format>
315 * line <lineno>
316 * line <first-lineno>-<last-lineno> // where either may be empty
Jim Cromie820874c2011-12-19 17:12:49 -0500317 *
318 * Only 1 of each type is allowed.
319 * Returns 0 on success, <0 on error.
Jason Barone9d376f2009-02-05 11:51:38 -0500320 */
321static int ddebug_parse_query(char *words[], int nwords,
322 struct ddebug_query *query)
323{
324 unsigned int i;
Jim Cromie820874c2011-12-19 17:12:49 -0500325 int rc;
Jason Barone9d376f2009-02-05 11:51:38 -0500326
327 /* check we have an even number of words */
328 if (nwords % 2 != 0)
329 return -EINVAL;
330 memset(query, 0, sizeof(*query));
331
332 for (i = 0 ; i < nwords ; i += 2) {
333 if (!strcmp(words[i], "func"))
Jim Cromie820874c2011-12-19 17:12:49 -0500334 rc = check_set(&query->function, words[i+1], "func");
Jason Barone9d376f2009-02-05 11:51:38 -0500335 else if (!strcmp(words[i], "file"))
Jim Cromie820874c2011-12-19 17:12:49 -0500336 rc = check_set(&query->filename, words[i+1], "file");
Jason Barone9d376f2009-02-05 11:51:38 -0500337 else if (!strcmp(words[i], "module"))
Jim Cromie820874c2011-12-19 17:12:49 -0500338 rc = check_set(&query->module, words[i+1], "module");
Jason Barone9d376f2009-02-05 11:51:38 -0500339 else if (!strcmp(words[i], "format"))
Jim Cromie820874c2011-12-19 17:12:49 -0500340 rc = check_set(&query->format, unescape(words[i+1]),
341 "format");
Jason Barone9d376f2009-02-05 11:51:38 -0500342 else if (!strcmp(words[i], "line")) {
343 char *first = words[i+1];
344 char *last = strchr(first, '-');
Jim Cromie820874c2011-12-19 17:12:49 -0500345 if (query->first_lineno || query->last_lineno) {
346 pr_err("match-spec:line given 2 times\n");
347 return -EINVAL;
348 }
Jason Barone9d376f2009-02-05 11:51:38 -0500349 if (last)
350 *last++ = '\0';
351 if (parse_lineno(first, &query->first_lineno) < 0)
352 return -EINVAL;
Jim Cromie820874c2011-12-19 17:12:49 -0500353 if (last) {
Jason Barone9d376f2009-02-05 11:51:38 -0500354 /* range <first>-<last> */
Jim Cromie820874c2011-12-19 17:12:49 -0500355 if (parse_lineno(last, &query->last_lineno)
356 < query->first_lineno) {
357 pr_err("last-line < 1st-line\n");
Jason Barone9d376f2009-02-05 11:51:38 -0500358 return -EINVAL;
Jim Cromie820874c2011-12-19 17:12:49 -0500359 }
Jason Barone9d376f2009-02-05 11:51:38 -0500360 } else {
361 query->last_lineno = query->first_lineno;
362 }
363 } else {
Jim Cromieae27f862011-12-19 17:12:34 -0500364 pr_err("unknown keyword \"%s\"\n", words[i]);
Jason Barone9d376f2009-02-05 11:51:38 -0500365 return -EINVAL;
366 }
Jim Cromie820874c2011-12-19 17:12:49 -0500367 if (rc)
368 return rc;
Jason Barone9d376f2009-02-05 11:51:38 -0500369 }
370
371 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400372 pr_info("q->function=\"%s\" q->filename=\"%s\" "
373 "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n",
374 query->function, query->filename,
Jason Barone9d376f2009-02-05 11:51:38 -0500375 query->module, query->format, query->first_lineno,
376 query->last_lineno);
377
378 return 0;
379}
380
381/*
382 * Parse `str' as a flags specification, format [-+=][p]+.
383 * Sets up *maskp and *flagsp to be used when changing the
384 * flags fields of matched _ddebug's. Returns 0 on success
385 * or <0 on error.
386 */
387static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
388 unsigned int *maskp)
389{
390 unsigned flags = 0;
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100391 int op = '=', i;
Jason Barone9d376f2009-02-05 11:51:38 -0500392
393 switch (*str) {
394 case '+':
395 case '-':
396 case '=':
397 op = *str++;
398 break;
399 default:
400 return -EINVAL;
401 }
402 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400403 pr_info("op='%c'\n", op);
Jason Barone9d376f2009-02-05 11:51:38 -0500404
405 for ( ; *str ; ++str) {
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100406 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
407 if (*str == opt_array[i].opt_char) {
408 flags |= opt_array[i].flag;
409 break;
410 }
Jason Barone9d376f2009-02-05 11:51:38 -0500411 }
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100412 if (i < 0)
413 return -EINVAL;
Jason Barone9d376f2009-02-05 11:51:38 -0500414 }
Jason Barone9d376f2009-02-05 11:51:38 -0500415 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400416 pr_info("flags=0x%x\n", flags);
Jason Barone9d376f2009-02-05 11:51:38 -0500417
418 /* calculate final *flagsp, *maskp according to mask and op */
419 switch (op) {
420 case '=':
421 *maskp = 0;
422 *flagsp = flags;
423 break;
424 case '+':
425 *maskp = ~0U;
426 *flagsp = flags;
427 break;
428 case '-':
429 *maskp = ~flags;
430 *flagsp = 0;
431 break;
432 }
433 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400434 pr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp);
Jason Barone9d376f2009-02-05 11:51:38 -0500435 return 0;
436}
437
Thomas Renningerfd89cfb2010-08-06 16:11:01 +0200438static int ddebug_exec_query(char *query_string)
439{
440 unsigned int flags = 0, mask = 0;
441 struct ddebug_query query;
442#define MAXWORDS 9
443 int nwords;
444 char *words[MAXWORDS];
445
446 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
447 if (nwords <= 0)
448 return -EINVAL;
449 if (ddebug_parse_query(words, nwords-1, &query))
450 return -EINVAL;
451 if (ddebug_parse_flags(words[nwords-1], &flags, &mask))
452 return -EINVAL;
453
454 /* actually go and implement the change */
455 ddebug_change(&query, flags, mask);
456 return 0;
457}
458
Jason Baron431625d2011-10-04 14:13:19 -0700459#define PREFIX_SIZE 64
460
461static int remaining(int wrote)
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100462{
Jason Baron431625d2011-10-04 14:13:19 -0700463 if (PREFIX_SIZE - wrote > 0)
464 return PREFIX_SIZE - wrote;
465 return 0;
466}
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100467
Jason Baron431625d2011-10-04 14:13:19 -0700468static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
469{
470 int pos_after_tid;
471 int pos = 0;
472
473 pos += snprintf(buf + pos, remaining(pos), "%s", KERN_DEBUG);
474 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100475 if (in_interrupt())
Jason Baron431625d2011-10-04 14:13:19 -0700476 pos += snprintf(buf + pos, remaining(pos), "%s ",
477 "<intr>");
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100478 else
Jason Baron431625d2011-10-04 14:13:19 -0700479 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
480 task_pid_vnr(current));
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100481 }
Jason Baron431625d2011-10-04 14:13:19 -0700482 pos_after_tid = pos;
483 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
484 pos += snprintf(buf + pos, remaining(pos), "%s:",
485 desc->modname);
486 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
487 pos += snprintf(buf + pos, remaining(pos), "%s:",
488 desc->function);
489 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
Jim Cromie07100be2011-12-19 17:11:09 -0500490 pos += snprintf(buf + pos, remaining(pos), "%d:",
491 desc->lineno);
Jason Baron431625d2011-10-04 14:13:19 -0700492 if (pos - pos_after_tid)
493 pos += snprintf(buf + pos, remaining(pos), " ");
494 if (pos >= PREFIX_SIZE)
495 buf[PREFIX_SIZE - 1] = '\0';
Joe Perches6c2140e2011-08-11 14:36:25 -0400496
Jason Baron431625d2011-10-04 14:13:19 -0700497 return buf;
Joe Perches6c2140e2011-08-11 14:36:25 -0400498}
499
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100500int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
501{
502 va_list args;
503 int res;
Jason Baron431625d2011-10-04 14:13:19 -0700504 struct va_format vaf;
505 char buf[PREFIX_SIZE];
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100506
507 BUG_ON(!descriptor);
508 BUG_ON(!fmt);
509
510 va_start(args, fmt);
Jason Baron431625d2011-10-04 14:13:19 -0700511 vaf.fmt = fmt;
512 vaf.va = &args;
513 res = printk("%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100514 va_end(args);
515
516 return res;
517}
518EXPORT_SYMBOL(__dynamic_pr_debug);
519
Joe Perchescbc46632011-08-11 14:36:21 -0400520int __dynamic_dev_dbg(struct _ddebug *descriptor,
521 const struct device *dev, const char *fmt, ...)
522{
523 struct va_format vaf;
524 va_list args;
525 int res;
Jason Baron431625d2011-10-04 14:13:19 -0700526 char buf[PREFIX_SIZE];
Joe Perchescbc46632011-08-11 14:36:21 -0400527
528 BUG_ON(!descriptor);
529 BUG_ON(!fmt);
530
531 va_start(args, fmt);
Joe Perchescbc46632011-08-11 14:36:21 -0400532 vaf.fmt = fmt;
533 vaf.va = &args;
Jason Baron431625d2011-10-04 14:13:19 -0700534 res = __dev_printk(dynamic_emit_prefix(descriptor, buf), dev, &vaf);
Joe Perchescbc46632011-08-11 14:36:21 -0400535 va_end(args);
536
537 return res;
538}
539EXPORT_SYMBOL(__dynamic_dev_dbg);
540
Jason Baron0feefd92011-10-04 14:13:22 -0700541#ifdef CONFIG_NET
542
Jason Baronffa10cb2011-08-11 14:36:48 -0400543int __dynamic_netdev_dbg(struct _ddebug *descriptor,
544 const struct net_device *dev, const char *fmt, ...)
545{
546 struct va_format vaf;
547 va_list args;
548 int res;
Jason Baron431625d2011-10-04 14:13:19 -0700549 char buf[PREFIX_SIZE];
Jason Baronffa10cb2011-08-11 14:36:48 -0400550
551 BUG_ON(!descriptor);
552 BUG_ON(!fmt);
553
554 va_start(args, fmt);
Jason Baronffa10cb2011-08-11 14:36:48 -0400555 vaf.fmt = fmt;
556 vaf.va = &args;
Jason Baron431625d2011-10-04 14:13:19 -0700557 res = __netdev_printk(dynamic_emit_prefix(descriptor, buf), dev, &vaf);
Jason Baronffa10cb2011-08-11 14:36:48 -0400558 va_end(args);
559
560 return res;
561}
562EXPORT_SYMBOL(__dynamic_netdev_dbg);
563
Jason Baron0feefd92011-10-04 14:13:22 -0700564#endif
565
Jim Cromiebc757f62011-12-19 17:12:29 -0500566#define DDEBUG_STRING_SIZE 1024
567static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
568
Thomas Renningera648ec02010-08-06 16:11:02 +0200569static __init int ddebug_setup_query(char *str)
570{
Jim Cromiebc757f62011-12-19 17:12:29 -0500571 if (strlen(str) >= DDEBUG_STRING_SIZE) {
Joe Perches4ad275e2011-08-11 14:36:33 -0400572 pr_warn("ddebug boot param string too large\n");
Thomas Renningera648ec02010-08-06 16:11:02 +0200573 return 0;
574 }
Jim Cromiebc757f62011-12-19 17:12:29 -0500575 strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
Thomas Renningera648ec02010-08-06 16:11:02 +0200576 return 1;
577}
578
579__setup("ddebug_query=", ddebug_setup_query);
580
Jason Barone9d376f2009-02-05 11:51:38 -0500581/*
582 * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the
583 * command text from userspace, parses and executes it.
584 */
Jim Cromie72814912011-12-19 17:13:07 -0500585#define USER_BUF_PAGE 4096
Jason Barone9d376f2009-02-05 11:51:38 -0500586static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
587 size_t len, loff_t *offp)
588{
Jim Cromie72814912011-12-19 17:13:07 -0500589 char *tmpbuf;
Thomas Renningerfd89cfb2010-08-06 16:11:01 +0200590 int ret;
Jason Barone9d376f2009-02-05 11:51:38 -0500591
592 if (len == 0)
593 return 0;
Jim Cromie72814912011-12-19 17:13:07 -0500594 if (len > USER_BUF_PAGE - 1) {
595 pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
Jason Barone9d376f2009-02-05 11:51:38 -0500596 return -E2BIG;
Jim Cromie72814912011-12-19 17:13:07 -0500597 }
598 tmpbuf = kmalloc(len + 1, GFP_KERNEL);
599 if (!tmpbuf)
600 return -ENOMEM;
601 if (copy_from_user(tmpbuf, ubuf, len)) {
602 kfree(tmpbuf);
Jason Barone9d376f2009-02-05 11:51:38 -0500603 return -EFAULT;
Jim Cromie72814912011-12-19 17:13:07 -0500604 }
Jason Barone9d376f2009-02-05 11:51:38 -0500605 tmpbuf[len] = '\0';
606 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400607 pr_info("read %d bytes from userspace\n", (int)len);
Jason Barone9d376f2009-02-05 11:51:38 -0500608
Thomas Renningerfd89cfb2010-08-06 16:11:01 +0200609 ret = ddebug_exec_query(tmpbuf);
Jim Cromie72814912011-12-19 17:13:07 -0500610 kfree(tmpbuf);
Thomas Renningerfd89cfb2010-08-06 16:11:01 +0200611 if (ret)
612 return ret;
Jason Barone9d376f2009-02-05 11:51:38 -0500613
614 *offp += len;
615 return len;
616}
617
618/*
619 * Set the iterator to point to the first _ddebug object
620 * and return a pointer to that first object. Returns
621 * NULL if there are no _ddebugs at all.
622 */
623static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
624{
625 if (list_empty(&ddebug_tables)) {
626 iter->table = NULL;
627 iter->idx = 0;
628 return NULL;
629 }
630 iter->table = list_entry(ddebug_tables.next,
631 struct ddebug_table, link);
632 iter->idx = 0;
633 return &iter->table->ddebugs[iter->idx];
634}
635
636/*
637 * Advance the iterator to point to the next _ddebug
638 * object from the one the iterator currently points at,
639 * and returns a pointer to the new _ddebug. Returns
640 * NULL if the iterator has seen all the _ddebugs.
641 */
642static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
643{
644 if (iter->table == NULL)
645 return NULL;
646 if (++iter->idx == iter->table->num_ddebugs) {
647 /* iterate to next table */
648 iter->idx = 0;
649 if (list_is_last(&iter->table->link, &ddebug_tables)) {
650 iter->table = NULL;
651 return NULL;
652 }
653 iter->table = list_entry(iter->table->link.next,
654 struct ddebug_table, link);
655 }
656 return &iter->table->ddebugs[iter->idx];
657}
658
659/*
660 * Seq_ops start method. Called at the start of every
661 * read() call from userspace. Takes the ddebug_lock and
662 * seeks the seq_file's iterator to the given position.
663 */
664static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
665{
666 struct ddebug_iter *iter = m->private;
667 struct _ddebug *dp;
668 int n = *pos;
669
670 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400671 pr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos);
Jason Barone9d376f2009-02-05 11:51:38 -0500672
673 mutex_lock(&ddebug_lock);
674
675 if (!n)
676 return SEQ_START_TOKEN;
677 if (n < 0)
678 return NULL;
679 dp = ddebug_iter_first(iter);
680 while (dp != NULL && --n > 0)
681 dp = ddebug_iter_next(iter);
682 return dp;
683}
684
685/*
686 * Seq_ops next method. Called several times within a read()
687 * call from userspace, with ddebug_lock held. Walks to the
688 * next _ddebug object with a special case for the header line.
689 */
690static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
691{
692 struct ddebug_iter *iter = m->private;
693 struct _ddebug *dp;
694
695 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400696 pr_info("called m=%p p=%p *pos=%lld\n",
697 m, p, (unsigned long long)*pos);
Jason Barone9d376f2009-02-05 11:51:38 -0500698
699 if (p == SEQ_START_TOKEN)
700 dp = ddebug_iter_first(iter);
701 else
702 dp = ddebug_iter_next(iter);
703 ++*pos;
704 return dp;
705}
706
707/*
708 * Seq_ops show method. Called several times within a read()
709 * call from userspace, with ddebug_lock held. Formats the
710 * current _ddebug as a single human-readable line, with a
711 * special case for the header line.
712 */
713static int ddebug_proc_show(struct seq_file *m, void *p)
714{
715 struct ddebug_iter *iter = m->private;
716 struct _ddebug *dp = p;
Jim Cromie5ca7d2a2011-12-19 17:12:44 -0500717 char flagsbuf[10];
Jason Barone9d376f2009-02-05 11:51:38 -0500718
719 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400720 pr_info("called m=%p p=%p\n", m, p);
Jason Barone9d376f2009-02-05 11:51:38 -0500721
722 if (p == SEQ_START_TOKEN) {
723 seq_puts(m,
724 "# filename:lineno [module]function flags format\n");
725 return 0;
726 }
727
Jim Cromie5ca7d2a2011-12-19 17:12:44 -0500728 seq_printf(m, "%s:%u [%s]%s =%s \"",
Jim Cromie2b678312011-12-19 17:13:12 -0500729 trim_prefix(dp->filename), dp->lineno,
Jim Cromie5ca7d2a2011-12-19 17:12:44 -0500730 iter->table->mod_name, dp->function,
731 ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
Jason Barone9d376f2009-02-05 11:51:38 -0500732 seq_escape(m, dp->format, "\t\r\n\"");
733 seq_puts(m, "\"\n");
734
735 return 0;
736}
737
738/*
739 * Seq_ops stop method. Called at the end of each read()
740 * call from userspace. Drops ddebug_lock.
741 */
742static void ddebug_proc_stop(struct seq_file *m, void *p)
743{
744 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400745 pr_info("called m=%p p=%p\n", m, p);
Jason Barone9d376f2009-02-05 11:51:38 -0500746 mutex_unlock(&ddebug_lock);
747}
748
749static const struct seq_operations ddebug_proc_seqops = {
750 .start = ddebug_proc_start,
751 .next = ddebug_proc_next,
752 .show = ddebug_proc_show,
753 .stop = ddebug_proc_stop
754};
755
756/*
Jim Cromie07100be2011-12-19 17:11:09 -0500757 * File_ops->open method for <debugfs>/dynamic_debug/control. Does
758 * the seq_file setup dance, and also creates an iterator to walk the
759 * _ddebugs. Note that we create a seq_file always, even for O_WRONLY
760 * files where it's not needed, as doing so simplifies the ->release
761 * method.
Jason Barone9d376f2009-02-05 11:51:38 -0500762 */
763static int ddebug_proc_open(struct inode *inode, struct file *file)
764{
765 struct ddebug_iter *iter;
766 int err;
767
768 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400769 pr_info("called\n");
Jason Barone9d376f2009-02-05 11:51:38 -0500770
771 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
772 if (iter == NULL)
773 return -ENOMEM;
774
775 err = seq_open(file, &ddebug_proc_seqops);
776 if (err) {
777 kfree(iter);
778 return err;
779 }
780 ((struct seq_file *) file->private_data)->private = iter;
781 return 0;
782}
783
784static const struct file_operations ddebug_proc_fops = {
785 .owner = THIS_MODULE,
786 .open = ddebug_proc_open,
787 .read = seq_read,
788 .llseek = seq_lseek,
789 .release = seq_release_private,
790 .write = ddebug_proc_write
791};
792
793/*
794 * Allocate a new ddebug_table for the given module
795 * and add it to the global list.
796 */
797int ddebug_add_module(struct _ddebug *tab, unsigned int n,
798 const char *name)
799{
800 struct ddebug_table *dt;
801 char *new_name;
802
803 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
804 if (dt == NULL)
805 return -ENOMEM;
806 new_name = kstrdup(name, GFP_KERNEL);
807 if (new_name == NULL) {
808 kfree(dt);
809 return -ENOMEM;
810 }
811 dt->mod_name = new_name;
812 dt->num_ddebugs = n;
Jason Barone9d376f2009-02-05 11:51:38 -0500813 dt->ddebugs = tab;
814
815 mutex_lock(&ddebug_lock);
816 list_add_tail(&dt->link, &ddebug_tables);
817 mutex_unlock(&ddebug_lock);
818
819 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400820 pr_info("%u debug prints in module %s\n", n, dt->mod_name);
Jason Barone9d376f2009-02-05 11:51:38 -0500821 return 0;
822}
823EXPORT_SYMBOL_GPL(ddebug_add_module);
824
825static void ddebug_table_free(struct ddebug_table *dt)
826{
827 list_del_init(&dt->link);
828 kfree(dt->mod_name);
829 kfree(dt);
830}
831
832/*
833 * Called in response to a module being unloaded. Removes
834 * any ddebug_table's which point at the module.
835 */
Yehuda Sadehff49d742010-07-03 13:07:35 +1000836int ddebug_remove_module(const char *mod_name)
Jason Barone9d376f2009-02-05 11:51:38 -0500837{
838 struct ddebug_table *dt, *nextdt;
839 int ret = -ENOENT;
840
841 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400842 pr_info("removing module \"%s\"\n", mod_name);
Jason Barone9d376f2009-02-05 11:51:38 -0500843
844 mutex_lock(&ddebug_lock);
845 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
846 if (!strcmp(dt->mod_name, mod_name)) {
847 ddebug_table_free(dt);
848 ret = 0;
849 }
850 }
851 mutex_unlock(&ddebug_lock);
852 return ret;
853}
854EXPORT_SYMBOL_GPL(ddebug_remove_module);
855
856static void ddebug_remove_all_tables(void)
857{
858 mutex_lock(&ddebug_lock);
859 while (!list_empty(&ddebug_tables)) {
860 struct ddebug_table *dt = list_entry(ddebug_tables.next,
861 struct ddebug_table,
862 link);
863 ddebug_table_free(dt);
864 }
865 mutex_unlock(&ddebug_lock);
866}
867
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200868static __initdata int ddebug_init_success;
869
870static int __init dynamic_debug_init_debugfs(void)
Jason Barone9d376f2009-02-05 11:51:38 -0500871{
872 struct dentry *dir, *file;
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200873
874 if (!ddebug_init_success)
875 return -ENODEV;
Jason Barone9d376f2009-02-05 11:51:38 -0500876
877 dir = debugfs_create_dir("dynamic_debug", NULL);
878 if (!dir)
879 return -ENOMEM;
880 file = debugfs_create_file("control", 0644, dir, NULL,
881 &ddebug_proc_fops);
882 if (!file) {
883 debugfs_remove(dir);
884 return -ENOMEM;
885 }
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200886 return 0;
887}
888
889static int __init dynamic_debug_init(void)
890{
891 struct _ddebug *iter, *iter_start;
892 const char *modname = NULL;
893 int ret = 0;
894 int n = 0;
895
Jim Cromieb5b78f82011-12-19 17:12:54 -0500896 if (__start___verbose == __stop___verbose) {
897 pr_warn("_ddebug table is empty in a "
898 "CONFIG_DYNAMIC_DEBUG build");
899 return 1;
Jason Barone9d376f2009-02-05 11:51:38 -0500900 }
Jim Cromieb5b78f82011-12-19 17:12:54 -0500901 iter = __start___verbose;
902 modname = iter->modname;
903 iter_start = iter;
904 for (; iter < __stop___verbose; iter++) {
905 if (strcmp(modname, iter->modname)) {
906 ret = ddebug_add_module(iter_start, n, modname);
907 if (ret)
908 goto out_free;
909 n = 0;
910 modname = iter->modname;
911 iter_start = iter;
912 }
913 n++;
914 }
915 ret = ddebug_add_module(iter_start, n, modname);
916 if (ret)
917 goto out_free;
Thomas Renningera648ec02010-08-06 16:11:02 +0200918
919 /* ddebug_query boot param got passed -> set it up */
920 if (ddebug_setup_string[0] != '\0') {
921 ret = ddebug_exec_query(ddebug_setup_string);
922 if (ret)
Joe Perches4ad275e2011-08-11 14:36:33 -0400923 pr_warn("Invalid ddebug boot param %s",
924 ddebug_setup_string);
Thomas Renningera648ec02010-08-06 16:11:02 +0200925 else
926 pr_info("ddebug initialized with string %s",
927 ddebug_setup_string);
Jason Barone9d376f2009-02-05 11:51:38 -0500928 }
Thomas Renningera648ec02010-08-06 16:11:02 +0200929
Jason Barone9d376f2009-02-05 11:51:38 -0500930out_free:
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200931 if (ret)
Jason Barone9d376f2009-02-05 11:51:38 -0500932 ddebug_remove_all_tables();
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200933 else
934 ddebug_init_success = 1;
Jason Barone9d376f2009-02-05 11:51:38 -0500935 return 0;
936}
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200937/* Allow early initialization for boot messages via boot param */
938arch_initcall(dynamic_debug_init);
939/* Debugfs setup must be done later */
940module_init(dynamic_debug_init_debugfs);