blob: b199e093505341c680940e56c9315803eac6bb49 [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
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010072static struct { unsigned flag:8; char opt_char; } opt_array[] = {
73 { _DPRINTK_FLAGS_PRINT, 'p' },
74 { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
75 { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
76 { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
77 { _DPRINTK_FLAGS_INCL_TID, 't' },
78};
79
Jason Barone9d376f2009-02-05 11:51:38 -050080/* format a string into buf[] which describes the _ddebug's flags */
81static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
82 size_t maxlen)
83{
84 char *p = buf;
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010085 int i;
Jason Barone9d376f2009-02-05 11:51:38 -050086
87 BUG_ON(maxlen < 4);
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010088 for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
89 if (dp->flags & opt_array[i].flag)
90 *p++ = opt_array[i].opt_char;
Jason Barone9d376f2009-02-05 11:51:38 -050091 if (p == buf)
92 *p++ = '-';
93 *p = '\0';
94
95 return buf;
96}
97
98/*
Jason Barone9d376f2009-02-05 11:51:38 -050099 * Search the tables for _ddebug's which match the given
100 * `query' and apply the `flags' and `mask' to them. Tells
101 * the user which ddebug's were changed, or whether none
102 * were matched.
103 */
104static void ddebug_change(const struct ddebug_query *query,
105 unsigned int flags, unsigned int mask)
106{
107 int i;
108 struct ddebug_table *dt;
109 unsigned int newflags;
110 unsigned int nfound = 0;
111 char flagbuf[8];
112
113 /* search for matching ddebugs */
114 mutex_lock(&ddebug_lock);
115 list_for_each_entry(dt, &ddebug_tables, link) {
116
117 /* match against the module name */
Jim Cromied6a238d2011-12-19 17:12:39 -0500118 if (query->module && strcmp(query->module, dt->mod_name))
Jason Barone9d376f2009-02-05 11:51:38 -0500119 continue;
120
121 for (i = 0 ; i < dt->num_ddebugs ; i++) {
122 struct _ddebug *dp = &dt->ddebugs[i];
123
124 /* match against the source filename */
Jim Cromied6a238d2011-12-19 17:12:39 -0500125 if (query->filename &&
Jason Barone9d376f2009-02-05 11:51:38 -0500126 strcmp(query->filename, dp->filename) &&
127 strcmp(query->filename, basename(dp->filename)))
128 continue;
129
130 /* match against the function */
Jim Cromied6a238d2011-12-19 17:12:39 -0500131 if (query->function &&
Jason Barone9d376f2009-02-05 11:51:38 -0500132 strcmp(query->function, dp->function))
133 continue;
134
135 /* match against the format */
Jim Cromied6a238d2011-12-19 17:12:39 -0500136 if (query->format &&
137 !strstr(dp->format, query->format))
Jason Barone9d376f2009-02-05 11:51:38 -0500138 continue;
139
140 /* match against the line number range */
141 if (query->first_lineno &&
142 dp->lineno < query->first_lineno)
143 continue;
144 if (query->last_lineno &&
145 dp->lineno > query->last_lineno)
146 continue;
147
148 nfound++;
149
150 newflags = (dp->flags & mask) | flags;
151 if (newflags == dp->flags)
152 continue;
Jason Barone9d376f2009-02-05 11:51:38 -0500153 dp->flags = newflags;
Jason Barone9d376f2009-02-05 11:51:38 -0500154 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400155 pr_info("changed %s:%d [%s]%s %s\n",
Jason Barone9d376f2009-02-05 11:51:38 -0500156 dp->filename, dp->lineno,
157 dt->mod_name, dp->function,
158 ddebug_describe_flags(dp, flagbuf,
159 sizeof(flagbuf)));
160 }
161 }
162 mutex_unlock(&ddebug_lock);
163
164 if (!nfound && verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400165 pr_info("no matches for query\n");
Jason Barone9d376f2009-02-05 11:51:38 -0500166}
167
168/*
Jason Barone9d376f2009-02-05 11:51:38 -0500169 * Split the buffer `buf' into space-separated words.
Greg Banks9898abb2009-02-06 12:54:26 +1100170 * Handles simple " and ' quoting, i.e. without nested,
171 * embedded or escaped \". Return the number of words
172 * or <0 on error.
Jason Barone9d376f2009-02-05 11:51:38 -0500173 */
174static int ddebug_tokenize(char *buf, char *words[], int maxwords)
175{
176 int nwords = 0;
177
Greg Banks9898abb2009-02-06 12:54:26 +1100178 while (*buf) {
179 char *end;
180
181 /* Skip leading whitespace */
André Goddard Rosae7d28602009-12-14 18:01:06 -0800182 buf = skip_spaces(buf);
Greg Banks9898abb2009-02-06 12:54:26 +1100183 if (!*buf)
184 break; /* oh, it was trailing whitespace */
185
Jim Cromie07100be2011-12-19 17:11:09 -0500186 /* find `end' of word, whitespace separated or quoted */
Greg Banks9898abb2009-02-06 12:54:26 +1100187 if (*buf == '"' || *buf == '\'') {
188 int quote = *buf++;
189 for (end = buf ; *end && *end != quote ; end++)
190 ;
191 if (!*end)
192 return -EINVAL; /* unclosed quote */
193 } else {
194 for (end = buf ; *end && !isspace(*end) ; end++)
195 ;
196 BUG_ON(end == buf);
197 }
Greg Banks9898abb2009-02-06 12:54:26 +1100198
Jim Cromie07100be2011-12-19 17:11:09 -0500199 /* `buf' is start of word, `end' is one past its end */
Greg Banks9898abb2009-02-06 12:54:26 +1100200 if (nwords == maxwords)
201 return -EINVAL; /* ran out of words[] before bytes */
202 if (*end)
203 *end++ = '\0'; /* terminate the word */
204 words[nwords++] = buf;
205 buf = end;
206 }
Jason Barone9d376f2009-02-05 11:51:38 -0500207
208 if (verbose) {
209 int i;
Joe Perches4ad275e2011-08-11 14:36:33 -0400210 pr_info("split into words:");
Jason Barone9d376f2009-02-05 11:51:38 -0500211 for (i = 0 ; i < nwords ; i++)
Joe Perches4ad275e2011-08-11 14:36:33 -0400212 pr_cont(" \"%s\"", words[i]);
213 pr_cont("\n");
Jason Barone9d376f2009-02-05 11:51:38 -0500214 }
215
216 return nwords;
217}
218
219/*
220 * Parse a single line number. Note that the empty string ""
221 * is treated as a special case and converted to zero, which
222 * is later treated as a "don't care" value.
223 */
224static inline int parse_lineno(const char *str, unsigned int *val)
225{
226 char *end = NULL;
227 BUG_ON(str == NULL);
228 if (*str == '\0') {
229 *val = 0;
230 return 0;
231 }
232 *val = simple_strtoul(str, &end, 10);
233 return end == NULL || end == str || *end != '\0' ? -EINVAL : 0;
234}
235
236/*
237 * Undo octal escaping in a string, inplace. This is useful to
238 * allow the user to express a query which matches a format
239 * containing embedded spaces.
240 */
241#define isodigit(c) ((c) >= '0' && (c) <= '7')
242static char *unescape(char *str)
243{
244 char *in = str;
245 char *out = str;
246
247 while (*in) {
248 if (*in == '\\') {
249 if (in[1] == '\\') {
250 *out++ = '\\';
251 in += 2;
252 continue;
253 } else if (in[1] == 't') {
254 *out++ = '\t';
255 in += 2;
256 continue;
257 } else if (in[1] == 'n') {
258 *out++ = '\n';
259 in += 2;
260 continue;
261 } else if (isodigit(in[1]) &&
262 isodigit(in[2]) &&
263 isodigit(in[3])) {
264 *out++ = ((in[1] - '0')<<6) |
265 ((in[2] - '0')<<3) |
266 (in[3] - '0');
267 in += 4;
268 continue;
269 }
270 }
271 *out++ = *in++;
272 }
273 *out = '\0';
274
275 return str;
276}
277
278/*
279 * Parse words[] as a ddebug query specification, which is a series
280 * of (keyword, value) pairs chosen from these possibilities:
281 *
282 * func <function-name>
283 * file <full-pathname>
284 * file <base-filename>
285 * module <module-name>
286 * format <escaped-string-to-find-in-format>
287 * line <lineno>
288 * line <first-lineno>-<last-lineno> // where either may be empty
289 */
290static int ddebug_parse_query(char *words[], int nwords,
291 struct ddebug_query *query)
292{
293 unsigned int i;
294
295 /* check we have an even number of words */
296 if (nwords % 2 != 0)
297 return -EINVAL;
298 memset(query, 0, sizeof(*query));
299
300 for (i = 0 ; i < nwords ; i += 2) {
301 if (!strcmp(words[i], "func"))
302 query->function = words[i+1];
303 else if (!strcmp(words[i], "file"))
304 query->filename = words[i+1];
305 else if (!strcmp(words[i], "module"))
306 query->module = words[i+1];
307 else if (!strcmp(words[i], "format"))
308 query->format = unescape(words[i+1]);
309 else if (!strcmp(words[i], "line")) {
310 char *first = words[i+1];
311 char *last = strchr(first, '-');
312 if (last)
313 *last++ = '\0';
314 if (parse_lineno(first, &query->first_lineno) < 0)
315 return -EINVAL;
316 if (last != NULL) {
317 /* range <first>-<last> */
318 if (parse_lineno(last, &query->last_lineno) < 0)
319 return -EINVAL;
320 } else {
321 query->last_lineno = query->first_lineno;
322 }
323 } else {
Jim Cromieae27f862011-12-19 17:12:34 -0500324 pr_err("unknown keyword \"%s\"\n", words[i]);
Jason Barone9d376f2009-02-05 11:51:38 -0500325 return -EINVAL;
326 }
327 }
328
329 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400330 pr_info("q->function=\"%s\" q->filename=\"%s\" "
331 "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n",
332 query->function, query->filename,
Jason Barone9d376f2009-02-05 11:51:38 -0500333 query->module, query->format, query->first_lineno,
334 query->last_lineno);
335
336 return 0;
337}
338
339/*
340 * Parse `str' as a flags specification, format [-+=][p]+.
341 * Sets up *maskp and *flagsp to be used when changing the
342 * flags fields of matched _ddebug's. Returns 0 on success
343 * or <0 on error.
344 */
345static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
346 unsigned int *maskp)
347{
348 unsigned flags = 0;
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100349 int op = '=', i;
Jason Barone9d376f2009-02-05 11:51:38 -0500350
351 switch (*str) {
352 case '+':
353 case '-':
354 case '=':
355 op = *str++;
356 break;
357 default:
358 return -EINVAL;
359 }
360 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400361 pr_info("op='%c'\n", op);
Jason Barone9d376f2009-02-05 11:51:38 -0500362
363 for ( ; *str ; ++str) {
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100364 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
365 if (*str == opt_array[i].opt_char) {
366 flags |= opt_array[i].flag;
367 break;
368 }
Jason Barone9d376f2009-02-05 11:51:38 -0500369 }
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100370 if (i < 0)
371 return -EINVAL;
Jason Barone9d376f2009-02-05 11:51:38 -0500372 }
373 if (flags == 0)
374 return -EINVAL;
375 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400376 pr_info("flags=0x%x\n", flags);
Jason Barone9d376f2009-02-05 11:51:38 -0500377
378 /* calculate final *flagsp, *maskp according to mask and op */
379 switch (op) {
380 case '=':
381 *maskp = 0;
382 *flagsp = flags;
383 break;
384 case '+':
385 *maskp = ~0U;
386 *flagsp = flags;
387 break;
388 case '-':
389 *maskp = ~flags;
390 *flagsp = 0;
391 break;
392 }
393 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400394 pr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp);
Jason Barone9d376f2009-02-05 11:51:38 -0500395 return 0;
396}
397
Thomas Renningerfd89cfb2010-08-06 16:11:01 +0200398static int ddebug_exec_query(char *query_string)
399{
400 unsigned int flags = 0, mask = 0;
401 struct ddebug_query query;
402#define MAXWORDS 9
403 int nwords;
404 char *words[MAXWORDS];
405
406 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
407 if (nwords <= 0)
408 return -EINVAL;
409 if (ddebug_parse_query(words, nwords-1, &query))
410 return -EINVAL;
411 if (ddebug_parse_flags(words[nwords-1], &flags, &mask))
412 return -EINVAL;
413
414 /* actually go and implement the change */
415 ddebug_change(&query, flags, mask);
416 return 0;
417}
418
Jason Baron431625d2011-10-04 14:13:19 -0700419#define PREFIX_SIZE 64
420
421static int remaining(int wrote)
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100422{
Jason Baron431625d2011-10-04 14:13:19 -0700423 if (PREFIX_SIZE - wrote > 0)
424 return PREFIX_SIZE - wrote;
425 return 0;
426}
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100427
Jason Baron431625d2011-10-04 14:13:19 -0700428static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
429{
430 int pos_after_tid;
431 int pos = 0;
432
433 pos += snprintf(buf + pos, remaining(pos), "%s", KERN_DEBUG);
434 if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100435 if (in_interrupt())
Jason Baron431625d2011-10-04 14:13:19 -0700436 pos += snprintf(buf + pos, remaining(pos), "%s ",
437 "<intr>");
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100438 else
Jason Baron431625d2011-10-04 14:13:19 -0700439 pos += snprintf(buf + pos, remaining(pos), "[%d] ",
440 task_pid_vnr(current));
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100441 }
Jason Baron431625d2011-10-04 14:13:19 -0700442 pos_after_tid = pos;
443 if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
444 pos += snprintf(buf + pos, remaining(pos), "%s:",
445 desc->modname);
446 if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
447 pos += snprintf(buf + pos, remaining(pos), "%s:",
448 desc->function);
449 if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
Jim Cromie07100be2011-12-19 17:11:09 -0500450 pos += snprintf(buf + pos, remaining(pos), "%d:",
451 desc->lineno);
Jason Baron431625d2011-10-04 14:13:19 -0700452 if (pos - pos_after_tid)
453 pos += snprintf(buf + pos, remaining(pos), " ");
454 if (pos >= PREFIX_SIZE)
455 buf[PREFIX_SIZE - 1] = '\0';
Joe Perches6c2140e2011-08-11 14:36:25 -0400456
Jason Baron431625d2011-10-04 14:13:19 -0700457 return buf;
Joe Perches6c2140e2011-08-11 14:36:25 -0400458}
459
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100460int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
461{
462 va_list args;
463 int res;
Jason Baron431625d2011-10-04 14:13:19 -0700464 struct va_format vaf;
465 char buf[PREFIX_SIZE];
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100466
467 BUG_ON(!descriptor);
468 BUG_ON(!fmt);
469
470 va_start(args, fmt);
Jason Baron431625d2011-10-04 14:13:19 -0700471 vaf.fmt = fmt;
472 vaf.va = &args;
473 res = printk("%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100474 va_end(args);
475
476 return res;
477}
478EXPORT_SYMBOL(__dynamic_pr_debug);
479
Joe Perchescbc46632011-08-11 14:36:21 -0400480int __dynamic_dev_dbg(struct _ddebug *descriptor,
481 const struct device *dev, const char *fmt, ...)
482{
483 struct va_format vaf;
484 va_list args;
485 int res;
Jason Baron431625d2011-10-04 14:13:19 -0700486 char buf[PREFIX_SIZE];
Joe Perchescbc46632011-08-11 14:36:21 -0400487
488 BUG_ON(!descriptor);
489 BUG_ON(!fmt);
490
491 va_start(args, fmt);
Joe Perchescbc46632011-08-11 14:36:21 -0400492 vaf.fmt = fmt;
493 vaf.va = &args;
Jason Baron431625d2011-10-04 14:13:19 -0700494 res = __dev_printk(dynamic_emit_prefix(descriptor, buf), dev, &vaf);
Joe Perchescbc46632011-08-11 14:36:21 -0400495 va_end(args);
496
497 return res;
498}
499EXPORT_SYMBOL(__dynamic_dev_dbg);
500
Jason Baron0feefd92011-10-04 14:13:22 -0700501#ifdef CONFIG_NET
502
Jason Baronffa10cb2011-08-11 14:36:48 -0400503int __dynamic_netdev_dbg(struct _ddebug *descriptor,
504 const struct net_device *dev, const char *fmt, ...)
505{
506 struct va_format vaf;
507 va_list args;
508 int res;
Jason Baron431625d2011-10-04 14:13:19 -0700509 char buf[PREFIX_SIZE];
Jason Baronffa10cb2011-08-11 14:36:48 -0400510
511 BUG_ON(!descriptor);
512 BUG_ON(!fmt);
513
514 va_start(args, fmt);
Jason Baronffa10cb2011-08-11 14:36:48 -0400515 vaf.fmt = fmt;
516 vaf.va = &args;
Jason Baron431625d2011-10-04 14:13:19 -0700517 res = __netdev_printk(dynamic_emit_prefix(descriptor, buf), dev, &vaf);
Jason Baronffa10cb2011-08-11 14:36:48 -0400518 va_end(args);
519
520 return res;
521}
522EXPORT_SYMBOL(__dynamic_netdev_dbg);
523
Jason Baron0feefd92011-10-04 14:13:22 -0700524#endif
525
Jim Cromiebc757f62011-12-19 17:12:29 -0500526#define DDEBUG_STRING_SIZE 1024
527static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
528
Thomas Renningera648ec02010-08-06 16:11:02 +0200529static __init int ddebug_setup_query(char *str)
530{
Jim Cromiebc757f62011-12-19 17:12:29 -0500531 if (strlen(str) >= DDEBUG_STRING_SIZE) {
Joe Perches4ad275e2011-08-11 14:36:33 -0400532 pr_warn("ddebug boot param string too large\n");
Thomas Renningera648ec02010-08-06 16:11:02 +0200533 return 0;
534 }
Jim Cromiebc757f62011-12-19 17:12:29 -0500535 strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
Thomas Renningera648ec02010-08-06 16:11:02 +0200536 return 1;
537}
538
539__setup("ddebug_query=", ddebug_setup_query);
540
Jason Barone9d376f2009-02-05 11:51:38 -0500541/*
542 * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the
543 * command text from userspace, parses and executes it.
544 */
545static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
546 size_t len, loff_t *offp)
547{
Jason Barone9d376f2009-02-05 11:51:38 -0500548 char tmpbuf[256];
Thomas Renningerfd89cfb2010-08-06 16:11:01 +0200549 int ret;
Jason Barone9d376f2009-02-05 11:51:38 -0500550
551 if (len == 0)
552 return 0;
553 /* we don't check *offp -- multiple writes() are allowed */
554 if (len > sizeof(tmpbuf)-1)
555 return -E2BIG;
556 if (copy_from_user(tmpbuf, ubuf, len))
557 return -EFAULT;
558 tmpbuf[len] = '\0';
559 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400560 pr_info("read %d bytes from userspace\n", (int)len);
Jason Barone9d376f2009-02-05 11:51:38 -0500561
Thomas Renningerfd89cfb2010-08-06 16:11:01 +0200562 ret = ddebug_exec_query(tmpbuf);
563 if (ret)
564 return ret;
Jason Barone9d376f2009-02-05 11:51:38 -0500565
566 *offp += len;
567 return len;
568}
569
570/*
571 * Set the iterator to point to the first _ddebug object
572 * and return a pointer to that first object. Returns
573 * NULL if there are no _ddebugs at all.
574 */
575static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
576{
577 if (list_empty(&ddebug_tables)) {
578 iter->table = NULL;
579 iter->idx = 0;
580 return NULL;
581 }
582 iter->table = list_entry(ddebug_tables.next,
583 struct ddebug_table, link);
584 iter->idx = 0;
585 return &iter->table->ddebugs[iter->idx];
586}
587
588/*
589 * Advance the iterator to point to the next _ddebug
590 * object from the one the iterator currently points at,
591 * and returns a pointer to the new _ddebug. Returns
592 * NULL if the iterator has seen all the _ddebugs.
593 */
594static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
595{
596 if (iter->table == NULL)
597 return NULL;
598 if (++iter->idx == iter->table->num_ddebugs) {
599 /* iterate to next table */
600 iter->idx = 0;
601 if (list_is_last(&iter->table->link, &ddebug_tables)) {
602 iter->table = NULL;
603 return NULL;
604 }
605 iter->table = list_entry(iter->table->link.next,
606 struct ddebug_table, link);
607 }
608 return &iter->table->ddebugs[iter->idx];
609}
610
611/*
612 * Seq_ops start method. Called at the start of every
613 * read() call from userspace. Takes the ddebug_lock and
614 * seeks the seq_file's iterator to the given position.
615 */
616static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
617{
618 struct ddebug_iter *iter = m->private;
619 struct _ddebug *dp;
620 int n = *pos;
621
622 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400623 pr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos);
Jason Barone9d376f2009-02-05 11:51:38 -0500624
625 mutex_lock(&ddebug_lock);
626
627 if (!n)
628 return SEQ_START_TOKEN;
629 if (n < 0)
630 return NULL;
631 dp = ddebug_iter_first(iter);
632 while (dp != NULL && --n > 0)
633 dp = ddebug_iter_next(iter);
634 return dp;
635}
636
637/*
638 * Seq_ops next method. Called several times within a read()
639 * call from userspace, with ddebug_lock held. Walks to the
640 * next _ddebug object with a special case for the header line.
641 */
642static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
643{
644 struct ddebug_iter *iter = m->private;
645 struct _ddebug *dp;
646
647 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400648 pr_info("called m=%p p=%p *pos=%lld\n",
649 m, p, (unsigned long long)*pos);
Jason Barone9d376f2009-02-05 11:51:38 -0500650
651 if (p == SEQ_START_TOKEN)
652 dp = ddebug_iter_first(iter);
653 else
654 dp = ddebug_iter_next(iter);
655 ++*pos;
656 return dp;
657}
658
659/*
660 * Seq_ops show method. Called several times within a read()
661 * call from userspace, with ddebug_lock held. Formats the
662 * current _ddebug as a single human-readable line, with a
663 * special case for the header line.
664 */
665static int ddebug_proc_show(struct seq_file *m, void *p)
666{
667 struct ddebug_iter *iter = m->private;
668 struct _ddebug *dp = p;
669 char flagsbuf[8];
670
671 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400672 pr_info("called m=%p p=%p\n", m, p);
Jason Barone9d376f2009-02-05 11:51:38 -0500673
674 if (p == SEQ_START_TOKEN) {
675 seq_puts(m,
676 "# filename:lineno [module]function flags format\n");
677 return 0;
678 }
679
680 seq_printf(m, "%s:%u [%s]%s %s \"",
681 dp->filename, dp->lineno,
682 iter->table->mod_name, dp->function,
683 ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
684 seq_escape(m, dp->format, "\t\r\n\"");
685 seq_puts(m, "\"\n");
686
687 return 0;
688}
689
690/*
691 * Seq_ops stop method. Called at the end of each read()
692 * call from userspace. Drops ddebug_lock.
693 */
694static void ddebug_proc_stop(struct seq_file *m, void *p)
695{
696 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400697 pr_info("called m=%p p=%p\n", m, p);
Jason Barone9d376f2009-02-05 11:51:38 -0500698 mutex_unlock(&ddebug_lock);
699}
700
701static const struct seq_operations ddebug_proc_seqops = {
702 .start = ddebug_proc_start,
703 .next = ddebug_proc_next,
704 .show = ddebug_proc_show,
705 .stop = ddebug_proc_stop
706};
707
708/*
Jim Cromie07100be2011-12-19 17:11:09 -0500709 * File_ops->open method for <debugfs>/dynamic_debug/control. Does
710 * the seq_file setup dance, and also creates an iterator to walk the
711 * _ddebugs. Note that we create a seq_file always, even for O_WRONLY
712 * files where it's not needed, as doing so simplifies the ->release
713 * method.
Jason Barone9d376f2009-02-05 11:51:38 -0500714 */
715static int ddebug_proc_open(struct inode *inode, struct file *file)
716{
717 struct ddebug_iter *iter;
718 int err;
719
720 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400721 pr_info("called\n");
Jason Barone9d376f2009-02-05 11:51:38 -0500722
723 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
724 if (iter == NULL)
725 return -ENOMEM;
726
727 err = seq_open(file, &ddebug_proc_seqops);
728 if (err) {
729 kfree(iter);
730 return err;
731 }
732 ((struct seq_file *) file->private_data)->private = iter;
733 return 0;
734}
735
736static const struct file_operations ddebug_proc_fops = {
737 .owner = THIS_MODULE,
738 .open = ddebug_proc_open,
739 .read = seq_read,
740 .llseek = seq_lseek,
741 .release = seq_release_private,
742 .write = ddebug_proc_write
743};
744
745/*
746 * Allocate a new ddebug_table for the given module
747 * and add it to the global list.
748 */
749int ddebug_add_module(struct _ddebug *tab, unsigned int n,
750 const char *name)
751{
752 struct ddebug_table *dt;
753 char *new_name;
754
755 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
756 if (dt == NULL)
757 return -ENOMEM;
758 new_name = kstrdup(name, GFP_KERNEL);
759 if (new_name == NULL) {
760 kfree(dt);
761 return -ENOMEM;
762 }
763 dt->mod_name = new_name;
764 dt->num_ddebugs = n;
Jason Barone9d376f2009-02-05 11:51:38 -0500765 dt->ddebugs = tab;
766
767 mutex_lock(&ddebug_lock);
768 list_add_tail(&dt->link, &ddebug_tables);
769 mutex_unlock(&ddebug_lock);
770
771 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400772 pr_info("%u debug prints in module %s\n", n, dt->mod_name);
Jason Barone9d376f2009-02-05 11:51:38 -0500773 return 0;
774}
775EXPORT_SYMBOL_GPL(ddebug_add_module);
776
777static void ddebug_table_free(struct ddebug_table *dt)
778{
779 list_del_init(&dt->link);
780 kfree(dt->mod_name);
781 kfree(dt);
782}
783
784/*
785 * Called in response to a module being unloaded. Removes
786 * any ddebug_table's which point at the module.
787 */
Yehuda Sadehff49d742010-07-03 13:07:35 +1000788int ddebug_remove_module(const char *mod_name)
Jason Barone9d376f2009-02-05 11:51:38 -0500789{
790 struct ddebug_table *dt, *nextdt;
791 int ret = -ENOENT;
792
793 if (verbose)
Joe Perches4ad275e2011-08-11 14:36:33 -0400794 pr_info("removing module \"%s\"\n", mod_name);
Jason Barone9d376f2009-02-05 11:51:38 -0500795
796 mutex_lock(&ddebug_lock);
797 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
798 if (!strcmp(dt->mod_name, mod_name)) {
799 ddebug_table_free(dt);
800 ret = 0;
801 }
802 }
803 mutex_unlock(&ddebug_lock);
804 return ret;
805}
806EXPORT_SYMBOL_GPL(ddebug_remove_module);
807
808static void ddebug_remove_all_tables(void)
809{
810 mutex_lock(&ddebug_lock);
811 while (!list_empty(&ddebug_tables)) {
812 struct ddebug_table *dt = list_entry(ddebug_tables.next,
813 struct ddebug_table,
814 link);
815 ddebug_table_free(dt);
816 }
817 mutex_unlock(&ddebug_lock);
818}
819
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200820static __initdata int ddebug_init_success;
821
822static int __init dynamic_debug_init_debugfs(void)
Jason Barone9d376f2009-02-05 11:51:38 -0500823{
824 struct dentry *dir, *file;
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200825
826 if (!ddebug_init_success)
827 return -ENODEV;
Jason Barone9d376f2009-02-05 11:51:38 -0500828
829 dir = debugfs_create_dir("dynamic_debug", NULL);
830 if (!dir)
831 return -ENOMEM;
832 file = debugfs_create_file("control", 0644, dir, NULL,
833 &ddebug_proc_fops);
834 if (!file) {
835 debugfs_remove(dir);
836 return -ENOMEM;
837 }
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200838 return 0;
839}
840
841static int __init dynamic_debug_init(void)
842{
843 struct _ddebug *iter, *iter_start;
844 const char *modname = NULL;
845 int ret = 0;
846 int n = 0;
847
Jason Barone9d376f2009-02-05 11:51:38 -0500848 if (__start___verbose != __stop___verbose) {
849 iter = __start___verbose;
850 modname = iter->modname;
851 iter_start = iter;
852 for (; iter < __stop___verbose; iter++) {
853 if (strcmp(modname, iter->modname)) {
854 ret = ddebug_add_module(iter_start, n, modname);
855 if (ret)
856 goto out_free;
857 n = 0;
858 modname = iter->modname;
859 iter_start = iter;
860 }
861 n++;
862 }
863 ret = ddebug_add_module(iter_start, n, modname);
864 }
Thomas Renningera648ec02010-08-06 16:11:02 +0200865
866 /* ddebug_query boot param got passed -> set it up */
867 if (ddebug_setup_string[0] != '\0') {
868 ret = ddebug_exec_query(ddebug_setup_string);
869 if (ret)
Joe Perches4ad275e2011-08-11 14:36:33 -0400870 pr_warn("Invalid ddebug boot param %s",
871 ddebug_setup_string);
Thomas Renningera648ec02010-08-06 16:11:02 +0200872 else
873 pr_info("ddebug initialized with string %s",
874 ddebug_setup_string);
Jason Barone9d376f2009-02-05 11:51:38 -0500875 }
Thomas Renningera648ec02010-08-06 16:11:02 +0200876
Jason Barone9d376f2009-02-05 11:51:38 -0500877out_free:
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200878 if (ret)
Jason Barone9d376f2009-02-05 11:51:38 -0500879 ddebug_remove_all_tables();
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200880 else
881 ddebug_init_success = 1;
Jason Barone9d376f2009-02-05 11:51:38 -0500882 return 0;
883}
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200884/* Allow early initialization for boot messages via boot param */
885arch_initcall(dynamic_debug_init);
886/* Debugfs setup must be done later */
887module_init(dynamic_debug_init_debugfs);