Commit | Line | Data |
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e9d376f0 JB |
1 | /* |
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. | |
8ba6ebf5 | 10 | * Copyright (C) 2011 Bart Van Assche. All Rights Reserved. |
e9d376f0 JB |
11 | */ |
12 | ||
4ad275e5 JP |
13 | #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__ |
14 | ||
e9d376f0 JB |
15 | #include <linux/kernel.h> |
16 | #include <linux/module.h> | |
17 | #include <linux/moduleparam.h> | |
18 | #include <linux/kallsyms.h> | |
e9d376f0 JB |
19 | #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> | |
e7d2860b | 26 | #include <linux/string.h> |
e9d376f0 JB |
27 | #include <linux/uaccess.h> |
28 | #include <linux/dynamic_debug.h> | |
29 | #include <linux/debugfs.h> | |
5a0e3ad6 | 30 | #include <linux/slab.h> |
52159d98 | 31 | #include <linux/jump_label.h> |
8ba6ebf5 | 32 | #include <linux/hardirq.h> |
e8d9792a | 33 | #include <linux/sched.h> |
cbc46635 | 34 | #include <linux/device.h> |
ffa10cb4 | 35 | #include <linux/netdevice.h> |
e9d376f0 JB |
36 | |
37 | extern struct _ddebug __start___verbose[]; | |
38 | extern struct _ddebug __stop___verbose[]; | |
39 | ||
e9d376f0 JB |
40 | struct ddebug_table { |
41 | struct list_head link; | |
42 | char *mod_name; | |
43 | unsigned int num_ddebugs; | |
e9d376f0 JB |
44 | struct _ddebug *ddebugs; |
45 | }; | |
46 | ||
47 | struct 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 | ||
55 | struct ddebug_iter { | |
56 | struct ddebug_table *table; | |
57 | unsigned int idx; | |
58 | }; | |
59 | ||
60 | static DEFINE_MUTEX(ddebug_lock); | |
61 | static LIST_HEAD(ddebug_tables); | |
62 | static int verbose = 0; | |
74df138d | 63 | module_param(verbose, int, 0644); |
e9d376f0 JB |
64 | |
65 | /* Return the last part of a pathname */ | |
66 | static inline const char *basename(const char *path) | |
67 | { | |
68 | const char *tail = strrchr(path, '/'); | |
69 | return tail ? tail+1 : path; | |
70 | } | |
71 | ||
8ba6ebf5 BVA |
72 | static 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' }, | |
5ca7d2a6 | 78 | { _DPRINTK_FLAGS_NONE, '_' }, |
8ba6ebf5 BVA |
79 | }; |
80 | ||
e9d376f0 JB |
81 | /* format a string into buf[] which describes the _ddebug's flags */ |
82 | static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, | |
83 | size_t maxlen) | |
84 | { | |
85 | char *p = buf; | |
8ba6ebf5 | 86 | int i; |
e9d376f0 | 87 | |
5ca7d2a6 | 88 | BUG_ON(maxlen < 6); |
8ba6ebf5 BVA |
89 | for (i = 0; i < ARRAY_SIZE(opt_array); ++i) |
90 | if (dp->flags & opt_array[i].flag) | |
91 | *p++ = opt_array[i].opt_char; | |
e9d376f0 | 92 | if (p == buf) |
5ca7d2a6 | 93 | *p++ = '_'; |
e9d376f0 JB |
94 | *p = '\0'; |
95 | ||
96 | return buf; | |
97 | } | |
98 | ||
e9d376f0 JB |
99 | /* |
100 | * Search the tables for _ddebug's which match the given | |
101 | * `query' and apply the `flags' and `mask' to them. Tells | |
102 | * the user which ddebug's were changed, or whether none | |
103 | * were matched. | |
104 | */ | |
105 | static void ddebug_change(const struct ddebug_query *query, | |
106 | unsigned int flags, unsigned int mask) | |
107 | { | |
108 | int i; | |
109 | struct ddebug_table *dt; | |
110 | unsigned int newflags; | |
111 | unsigned int nfound = 0; | |
5ca7d2a6 | 112 | char flagbuf[10]; |
e9d376f0 JB |
113 | |
114 | /* search for matching ddebugs */ | |
115 | mutex_lock(&ddebug_lock); | |
116 | list_for_each_entry(dt, &ddebug_tables, link) { | |
117 | ||
118 | /* match against the module name */ | |
d6a238d2 | 119 | if (query->module && strcmp(query->module, dt->mod_name)) |
e9d376f0 JB |
120 | continue; |
121 | ||
122 | for (i = 0 ; i < dt->num_ddebugs ; i++) { | |
123 | struct _ddebug *dp = &dt->ddebugs[i]; | |
124 | ||
125 | /* match against the source filename */ | |
d6a238d2 | 126 | if (query->filename && |
e9d376f0 JB |
127 | strcmp(query->filename, dp->filename) && |
128 | strcmp(query->filename, basename(dp->filename))) | |
129 | continue; | |
130 | ||
131 | /* match against the function */ | |
d6a238d2 | 132 | if (query->function && |
e9d376f0 JB |
133 | strcmp(query->function, dp->function)) |
134 | continue; | |
135 | ||
136 | /* match against the format */ | |
d6a238d2 JC |
137 | if (query->format && |
138 | !strstr(dp->format, query->format)) | |
e9d376f0 JB |
139 | continue; |
140 | ||
141 | /* match against the line number range */ | |
142 | if (query->first_lineno && | |
143 | dp->lineno < query->first_lineno) | |
144 | continue; | |
145 | if (query->last_lineno && | |
146 | dp->lineno > query->last_lineno) | |
147 | continue; | |
148 | ||
149 | nfound++; | |
150 | ||
151 | newflags = (dp->flags & mask) | flags; | |
152 | if (newflags == dp->flags) | |
153 | continue; | |
e9d376f0 | 154 | dp->flags = newflags; |
e9d376f0 | 155 | if (verbose) |
5ca7d2a6 | 156 | pr_info("changed %s:%d [%s]%s =%s\n", |
e9d376f0 JB |
157 | dp->filename, dp->lineno, |
158 | dt->mod_name, dp->function, | |
159 | ddebug_describe_flags(dp, flagbuf, | |
160 | sizeof(flagbuf))); | |
161 | } | |
162 | } | |
163 | mutex_unlock(&ddebug_lock); | |
164 | ||
165 | if (!nfound && verbose) | |
4ad275e5 | 166 | pr_info("no matches for query\n"); |
e9d376f0 JB |
167 | } |
168 | ||
e9d376f0 JB |
169 | /* |
170 | * Split the buffer `buf' into space-separated words. | |
9898abb3 GB |
171 | * Handles simple " and ' quoting, i.e. without nested, |
172 | * embedded or escaped \". Return the number of words | |
173 | * or <0 on error. | |
e9d376f0 JB |
174 | */ |
175 | static int ddebug_tokenize(char *buf, char *words[], int maxwords) | |
176 | { | |
177 | int nwords = 0; | |
178 | ||
9898abb3 GB |
179 | while (*buf) { |
180 | char *end; | |
181 | ||
182 | /* Skip leading whitespace */ | |
e7d2860b | 183 | buf = skip_spaces(buf); |
9898abb3 GB |
184 | if (!*buf) |
185 | break; /* oh, it was trailing whitespace */ | |
186 | ||
07100be7 | 187 | /* find `end' of word, whitespace separated or quoted */ |
9898abb3 GB |
188 | if (*buf == '"' || *buf == '\'') { |
189 | int quote = *buf++; | |
190 | for (end = buf ; *end && *end != quote ; end++) | |
191 | ; | |
192 | if (!*end) | |
193 | return -EINVAL; /* unclosed quote */ | |
194 | } else { | |
195 | for (end = buf ; *end && !isspace(*end) ; end++) | |
196 | ; | |
197 | BUG_ON(end == buf); | |
198 | } | |
9898abb3 | 199 | |
07100be7 | 200 | /* `buf' is start of word, `end' is one past its end */ |
9898abb3 GB |
201 | if (nwords == maxwords) |
202 | return -EINVAL; /* ran out of words[] before bytes */ | |
203 | if (*end) | |
204 | *end++ = '\0'; /* terminate the word */ | |
205 | words[nwords++] = buf; | |
206 | buf = end; | |
207 | } | |
e9d376f0 JB |
208 | |
209 | if (verbose) { | |
210 | int i; | |
4ad275e5 | 211 | pr_info("split into words:"); |
e9d376f0 | 212 | for (i = 0 ; i < nwords ; i++) |
4ad275e5 JP |
213 | pr_cont(" \"%s\"", words[i]); |
214 | pr_cont("\n"); | |
e9d376f0 JB |
215 | } |
216 | ||
217 | return nwords; | |
218 | } | |
219 | ||
220 | /* | |
221 | * Parse a single line number. Note that the empty string "" | |
222 | * is treated as a special case and converted to zero, which | |
223 | * is later treated as a "don't care" value. | |
224 | */ | |
225 | static inline int parse_lineno(const char *str, unsigned int *val) | |
226 | { | |
227 | char *end = NULL; | |
228 | BUG_ON(str == NULL); | |
229 | if (*str == '\0') { | |
230 | *val = 0; | |
231 | return 0; | |
232 | } | |
233 | *val = simple_strtoul(str, &end, 10); | |
234 | return end == NULL || end == str || *end != '\0' ? -EINVAL : 0; | |
235 | } | |
236 | ||
237 | /* | |
238 | * Undo octal escaping in a string, inplace. This is useful to | |
239 | * allow the user to express a query which matches a format | |
240 | * containing embedded spaces. | |
241 | */ | |
242 | #define isodigit(c) ((c) >= '0' && (c) <= '7') | |
243 | static char *unescape(char *str) | |
244 | { | |
245 | char *in = str; | |
246 | char *out = str; | |
247 | ||
248 | while (*in) { | |
249 | if (*in == '\\') { | |
250 | if (in[1] == '\\') { | |
251 | *out++ = '\\'; | |
252 | in += 2; | |
253 | continue; | |
254 | } else if (in[1] == 't') { | |
255 | *out++ = '\t'; | |
256 | in += 2; | |
257 | continue; | |
258 | } else if (in[1] == 'n') { | |
259 | *out++ = '\n'; | |
260 | in += 2; | |
261 | continue; | |
262 | } else if (isodigit(in[1]) && | |
263 | isodigit(in[2]) && | |
264 | isodigit(in[3])) { | |
265 | *out++ = ((in[1] - '0')<<6) | | |
266 | ((in[2] - '0')<<3) | | |
267 | (in[3] - '0'); | |
268 | in += 4; | |
269 | continue; | |
270 | } | |
271 | } | |
272 | *out++ = *in++; | |
273 | } | |
274 | *out = '\0'; | |
275 | ||
276 | return str; | |
277 | } | |
278 | ||
820874c7 JC |
279 | static int check_set(const char **dest, char *src, char *name) |
280 | { | |
281 | int rc = 0; | |
282 | ||
283 | if (*dest) { | |
284 | rc = -EINVAL; | |
285 | pr_err("match-spec:%s val:%s overridden by %s", | |
286 | name, *dest, src); | |
287 | } | |
288 | *dest = src; | |
289 | return rc; | |
290 | } | |
291 | ||
e9d376f0 JB |
292 | /* |
293 | * Parse words[] as a ddebug query specification, which is a series | |
294 | * of (keyword, value) pairs chosen from these possibilities: | |
295 | * | |
296 | * func <function-name> | |
297 | * file <full-pathname> | |
298 | * file <base-filename> | |
299 | * module <module-name> | |
300 | * format <escaped-string-to-find-in-format> | |
301 | * line <lineno> | |
302 | * line <first-lineno>-<last-lineno> // where either may be empty | |
820874c7 JC |
303 | * |
304 | * Only 1 of each type is allowed. | |
305 | * Returns 0 on success, <0 on error. | |
e9d376f0 JB |
306 | */ |
307 | static int ddebug_parse_query(char *words[], int nwords, | |
308 | struct ddebug_query *query) | |
309 | { | |
310 | unsigned int i; | |
820874c7 | 311 | int rc; |
e9d376f0 JB |
312 | |
313 | /* check we have an even number of words */ | |
314 | if (nwords % 2 != 0) | |
315 | return -EINVAL; | |
316 | memset(query, 0, sizeof(*query)); | |
317 | ||
318 | for (i = 0 ; i < nwords ; i += 2) { | |
319 | if (!strcmp(words[i], "func")) | |
820874c7 | 320 | rc = check_set(&query->function, words[i+1], "func"); |
e9d376f0 | 321 | else if (!strcmp(words[i], "file")) |
820874c7 | 322 | rc = check_set(&query->filename, words[i+1], "file"); |
e9d376f0 | 323 | else if (!strcmp(words[i], "module")) |
820874c7 | 324 | rc = check_set(&query->module, words[i+1], "module"); |
e9d376f0 | 325 | else if (!strcmp(words[i], "format")) |
820874c7 JC |
326 | rc = check_set(&query->format, unescape(words[i+1]), |
327 | "format"); | |
e9d376f0 JB |
328 | else if (!strcmp(words[i], "line")) { |
329 | char *first = words[i+1]; | |
330 | char *last = strchr(first, '-'); | |
820874c7 JC |
331 | if (query->first_lineno || query->last_lineno) { |
332 | pr_err("match-spec:line given 2 times\n"); | |
333 | return -EINVAL; | |
334 | } | |
e9d376f0 JB |
335 | if (last) |
336 | *last++ = '\0'; | |
337 | if (parse_lineno(first, &query->first_lineno) < 0) | |
338 | return -EINVAL; | |
820874c7 | 339 | if (last) { |
e9d376f0 | 340 | /* range <first>-<last> */ |
820874c7 JC |
341 | if (parse_lineno(last, &query->last_lineno) |
342 | < query->first_lineno) { | |
343 | pr_err("last-line < 1st-line\n"); | |
e9d376f0 | 344 | return -EINVAL; |
820874c7 | 345 | } |
e9d376f0 JB |
346 | } else { |
347 | query->last_lineno = query->first_lineno; | |
348 | } | |
349 | } else { | |
ae27f86a | 350 | pr_err("unknown keyword \"%s\"\n", words[i]); |
e9d376f0 JB |
351 | return -EINVAL; |
352 | } | |
820874c7 JC |
353 | if (rc) |
354 | return rc; | |
e9d376f0 JB |
355 | } |
356 | ||
357 | if (verbose) | |
4ad275e5 JP |
358 | pr_info("q->function=\"%s\" q->filename=\"%s\" " |
359 | "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n", | |
360 | query->function, query->filename, | |
e9d376f0 JB |
361 | query->module, query->format, query->first_lineno, |
362 | query->last_lineno); | |
363 | ||
364 | return 0; | |
365 | } | |
366 | ||
367 | /* | |
368 | * Parse `str' as a flags specification, format [-+=][p]+. | |
369 | * Sets up *maskp and *flagsp to be used when changing the | |
370 | * flags fields of matched _ddebug's. Returns 0 on success | |
371 | * or <0 on error. | |
372 | */ | |
373 | static int ddebug_parse_flags(const char *str, unsigned int *flagsp, | |
374 | unsigned int *maskp) | |
375 | { | |
376 | unsigned flags = 0; | |
8ba6ebf5 | 377 | int op = '=', i; |
e9d376f0 JB |
378 | |
379 | switch (*str) { | |
380 | case '+': | |
381 | case '-': | |
382 | case '=': | |
383 | op = *str++; | |
384 | break; | |
385 | default: | |
386 | return -EINVAL; | |
387 | } | |
388 | if (verbose) | |
4ad275e5 | 389 | pr_info("op='%c'\n", op); |
e9d376f0 JB |
390 | |
391 | for ( ; *str ; ++str) { | |
8ba6ebf5 BVA |
392 | for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) { |
393 | if (*str == opt_array[i].opt_char) { | |
394 | flags |= opt_array[i].flag; | |
395 | break; | |
396 | } | |
e9d376f0 | 397 | } |
8ba6ebf5 BVA |
398 | if (i < 0) |
399 | return -EINVAL; | |
e9d376f0 | 400 | } |
e9d376f0 | 401 | if (verbose) |
4ad275e5 | 402 | pr_info("flags=0x%x\n", flags); |
e9d376f0 JB |
403 | |
404 | /* calculate final *flagsp, *maskp according to mask and op */ | |
405 | switch (op) { | |
406 | case '=': | |
407 | *maskp = 0; | |
408 | *flagsp = flags; | |
409 | break; | |
410 | case '+': | |
411 | *maskp = ~0U; | |
412 | *flagsp = flags; | |
413 | break; | |
414 | case '-': | |
415 | *maskp = ~flags; | |
416 | *flagsp = 0; | |
417 | break; | |
418 | } | |
419 | if (verbose) | |
4ad275e5 | 420 | pr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp); |
e9d376f0 JB |
421 | return 0; |
422 | } | |
423 | ||
fd89cfb8 TR |
424 | static int ddebug_exec_query(char *query_string) |
425 | { | |
426 | unsigned int flags = 0, mask = 0; | |
427 | struct ddebug_query query; | |
428 | #define MAXWORDS 9 | |
429 | int nwords; | |
430 | char *words[MAXWORDS]; | |
431 | ||
432 | nwords = ddebug_tokenize(query_string, words, MAXWORDS); | |
433 | if (nwords <= 0) | |
434 | return -EINVAL; | |
435 | if (ddebug_parse_query(words, nwords-1, &query)) | |
436 | return -EINVAL; | |
437 | if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) | |
438 | return -EINVAL; | |
439 | ||
440 | /* actually go and implement the change */ | |
441 | ddebug_change(&query, flags, mask); | |
442 | return 0; | |
443 | } | |
444 | ||
431625da JB |
445 | #define PREFIX_SIZE 64 |
446 | ||
447 | static int remaining(int wrote) | |
448 | { | |
449 | if (PREFIX_SIZE - wrote > 0) | |
450 | return PREFIX_SIZE - wrote; | |
451 | return 0; | |
452 | } | |
453 | ||
454 | static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf) | |
8ba6ebf5 | 455 | { |
431625da JB |
456 | int pos_after_tid; |
457 | int pos = 0; | |
8ba6ebf5 | 458 | |
431625da JB |
459 | pos += snprintf(buf + pos, remaining(pos), "%s", KERN_DEBUG); |
460 | if (desc->flags & _DPRINTK_FLAGS_INCL_TID) { | |
8ba6ebf5 | 461 | if (in_interrupt()) |
431625da JB |
462 | pos += snprintf(buf + pos, remaining(pos), "%s ", |
463 | "<intr>"); | |
8ba6ebf5 | 464 | else |
431625da JB |
465 | pos += snprintf(buf + pos, remaining(pos), "[%d] ", |
466 | task_pid_vnr(current)); | |
8ba6ebf5 | 467 | } |
431625da JB |
468 | pos_after_tid = pos; |
469 | if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME) | |
470 | pos += snprintf(buf + pos, remaining(pos), "%s:", | |
471 | desc->modname); | |
472 | if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME) | |
473 | pos += snprintf(buf + pos, remaining(pos), "%s:", | |
474 | desc->function); | |
475 | if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO) | |
07100be7 JC |
476 | pos += snprintf(buf + pos, remaining(pos), "%d:", |
477 | desc->lineno); | |
431625da JB |
478 | if (pos - pos_after_tid) |
479 | pos += snprintf(buf + pos, remaining(pos), " "); | |
480 | if (pos >= PREFIX_SIZE) | |
481 | buf[PREFIX_SIZE - 1] = '\0'; | |
6c2140ee | 482 | |
431625da | 483 | return buf; |
6c2140ee JP |
484 | } |
485 | ||
8ba6ebf5 BVA |
486 | int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...) |
487 | { | |
488 | va_list args; | |
489 | int res; | |
431625da JB |
490 | struct va_format vaf; |
491 | char buf[PREFIX_SIZE]; | |
8ba6ebf5 BVA |
492 | |
493 | BUG_ON(!descriptor); | |
494 | BUG_ON(!fmt); | |
495 | ||
496 | va_start(args, fmt); | |
431625da JB |
497 | vaf.fmt = fmt; |
498 | vaf.va = &args; | |
499 | res = printk("%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf); | |
8ba6ebf5 BVA |
500 | va_end(args); |
501 | ||
502 | return res; | |
503 | } | |
504 | EXPORT_SYMBOL(__dynamic_pr_debug); | |
505 | ||
cbc46635 JP |
506 | int __dynamic_dev_dbg(struct _ddebug *descriptor, |
507 | const struct device *dev, const char *fmt, ...) | |
508 | { | |
509 | struct va_format vaf; | |
510 | va_list args; | |
511 | int res; | |
431625da | 512 | char buf[PREFIX_SIZE]; |
cbc46635 JP |
513 | |
514 | BUG_ON(!descriptor); | |
515 | BUG_ON(!fmt); | |
516 | ||
517 | va_start(args, fmt); | |
cbc46635 JP |
518 | vaf.fmt = fmt; |
519 | vaf.va = &args; | |
431625da | 520 | res = __dev_printk(dynamic_emit_prefix(descriptor, buf), dev, &vaf); |
cbc46635 JP |
521 | va_end(args); |
522 | ||
523 | return res; | |
524 | } | |
525 | EXPORT_SYMBOL(__dynamic_dev_dbg); | |
526 | ||
0feefd97 JB |
527 | #ifdef CONFIG_NET |
528 | ||
ffa10cb4 JB |
529 | int __dynamic_netdev_dbg(struct _ddebug *descriptor, |
530 | const struct net_device *dev, const char *fmt, ...) | |
531 | { | |
532 | struct va_format vaf; | |
533 | va_list args; | |
534 | int res; | |
431625da | 535 | char buf[PREFIX_SIZE]; |
ffa10cb4 JB |
536 | |
537 | BUG_ON(!descriptor); | |
538 | BUG_ON(!fmt); | |
539 | ||
540 | va_start(args, fmt); | |
ffa10cb4 JB |
541 | vaf.fmt = fmt; |
542 | vaf.va = &args; | |
431625da | 543 | res = __netdev_printk(dynamic_emit_prefix(descriptor, buf), dev, &vaf); |
ffa10cb4 JB |
544 | va_end(args); |
545 | ||
546 | return res; | |
547 | } | |
548 | EXPORT_SYMBOL(__dynamic_netdev_dbg); | |
549 | ||
0feefd97 JB |
550 | #endif |
551 | ||
bc757f6f JC |
552 | #define DDEBUG_STRING_SIZE 1024 |
553 | static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE]; | |
554 | ||
a648ec05 TR |
555 | static __init int ddebug_setup_query(char *str) |
556 | { | |
bc757f6f | 557 | if (strlen(str) >= DDEBUG_STRING_SIZE) { |
4ad275e5 | 558 | pr_warn("ddebug boot param string too large\n"); |
a648ec05 TR |
559 | return 0; |
560 | } | |
bc757f6f | 561 | strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE); |
a648ec05 TR |
562 | return 1; |
563 | } | |
564 | ||
565 | __setup("ddebug_query=", ddebug_setup_query); | |
566 | ||
e9d376f0 JB |
567 | /* |
568 | * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the | |
569 | * command text from userspace, parses and executes it. | |
570 | */ | |
571 | static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, | |
572 | size_t len, loff_t *offp) | |
573 | { | |
e9d376f0 | 574 | char tmpbuf[256]; |
fd89cfb8 | 575 | int ret; |
e9d376f0 JB |
576 | |
577 | if (len == 0) | |
578 | return 0; | |
579 | /* we don't check *offp -- multiple writes() are allowed */ | |
580 | if (len > sizeof(tmpbuf)-1) | |
581 | return -E2BIG; | |
582 | if (copy_from_user(tmpbuf, ubuf, len)) | |
583 | return -EFAULT; | |
584 | tmpbuf[len] = '\0'; | |
585 | if (verbose) | |
4ad275e5 | 586 | pr_info("read %d bytes from userspace\n", (int)len); |
e9d376f0 | 587 | |
fd89cfb8 TR |
588 | ret = ddebug_exec_query(tmpbuf); |
589 | if (ret) | |
590 | return ret; | |
e9d376f0 JB |
591 | |
592 | *offp += len; | |
593 | return len; | |
594 | } | |
595 | ||
596 | /* | |
597 | * Set the iterator to point to the first _ddebug object | |
598 | * and return a pointer to that first object. Returns | |
599 | * NULL if there are no _ddebugs at all. | |
600 | */ | |
601 | static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter) | |
602 | { | |
603 | if (list_empty(&ddebug_tables)) { | |
604 | iter->table = NULL; | |
605 | iter->idx = 0; | |
606 | return NULL; | |
607 | } | |
608 | iter->table = list_entry(ddebug_tables.next, | |
609 | struct ddebug_table, link); | |
610 | iter->idx = 0; | |
611 | return &iter->table->ddebugs[iter->idx]; | |
612 | } | |
613 | ||
614 | /* | |
615 | * Advance the iterator to point to the next _ddebug | |
616 | * object from the one the iterator currently points at, | |
617 | * and returns a pointer to the new _ddebug. Returns | |
618 | * NULL if the iterator has seen all the _ddebugs. | |
619 | */ | |
620 | static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter) | |
621 | { | |
622 | if (iter->table == NULL) | |
623 | return NULL; | |
624 | if (++iter->idx == iter->table->num_ddebugs) { | |
625 | /* iterate to next table */ | |
626 | iter->idx = 0; | |
627 | if (list_is_last(&iter->table->link, &ddebug_tables)) { | |
628 | iter->table = NULL; | |
629 | return NULL; | |
630 | } | |
631 | iter->table = list_entry(iter->table->link.next, | |
632 | struct ddebug_table, link); | |
633 | } | |
634 | return &iter->table->ddebugs[iter->idx]; | |
635 | } | |
636 | ||
637 | /* | |
638 | * Seq_ops start method. Called at the start of every | |
639 | * read() call from userspace. Takes the ddebug_lock and | |
640 | * seeks the seq_file's iterator to the given position. | |
641 | */ | |
642 | static void *ddebug_proc_start(struct seq_file *m, loff_t *pos) | |
643 | { | |
644 | struct ddebug_iter *iter = m->private; | |
645 | struct _ddebug *dp; | |
646 | int n = *pos; | |
647 | ||
648 | if (verbose) | |
4ad275e5 | 649 | pr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos); |
e9d376f0 JB |
650 | |
651 | mutex_lock(&ddebug_lock); | |
652 | ||
653 | if (!n) | |
654 | return SEQ_START_TOKEN; | |
655 | if (n < 0) | |
656 | return NULL; | |
657 | dp = ddebug_iter_first(iter); | |
658 | while (dp != NULL && --n > 0) | |
659 | dp = ddebug_iter_next(iter); | |
660 | return dp; | |
661 | } | |
662 | ||
663 | /* | |
664 | * Seq_ops next method. Called several times within a read() | |
665 | * call from userspace, with ddebug_lock held. Walks to the | |
666 | * next _ddebug object with a special case for the header line. | |
667 | */ | |
668 | static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos) | |
669 | { | |
670 | struct ddebug_iter *iter = m->private; | |
671 | struct _ddebug *dp; | |
672 | ||
673 | if (verbose) | |
4ad275e5 JP |
674 | pr_info("called m=%p p=%p *pos=%lld\n", |
675 | m, p, (unsigned long long)*pos); | |
e9d376f0 JB |
676 | |
677 | if (p == SEQ_START_TOKEN) | |
678 | dp = ddebug_iter_first(iter); | |
679 | else | |
680 | dp = ddebug_iter_next(iter); | |
681 | ++*pos; | |
682 | return dp; | |
683 | } | |
684 | ||
685 | /* | |
686 | * Seq_ops show method. Called several times within a read() | |
687 | * call from userspace, with ddebug_lock held. Formats the | |
688 | * current _ddebug as a single human-readable line, with a | |
689 | * special case for the header line. | |
690 | */ | |
691 | static int ddebug_proc_show(struct seq_file *m, void *p) | |
692 | { | |
693 | struct ddebug_iter *iter = m->private; | |
694 | struct _ddebug *dp = p; | |
5ca7d2a6 | 695 | char flagsbuf[10]; |
e9d376f0 JB |
696 | |
697 | if (verbose) | |
4ad275e5 | 698 | pr_info("called m=%p p=%p\n", m, p); |
e9d376f0 JB |
699 | |
700 | if (p == SEQ_START_TOKEN) { | |
701 | seq_puts(m, | |
702 | "# filename:lineno [module]function flags format\n"); | |
703 | return 0; | |
704 | } | |
705 | ||
5ca7d2a6 JC |
706 | seq_printf(m, "%s:%u [%s]%s =%s \"", |
707 | dp->filename, dp->lineno, | |
708 | iter->table->mod_name, dp->function, | |
709 | ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf))); | |
e9d376f0 JB |
710 | seq_escape(m, dp->format, "\t\r\n\""); |
711 | seq_puts(m, "\"\n"); | |
712 | ||
713 | return 0; | |
714 | } | |
715 | ||
716 | /* | |
717 | * Seq_ops stop method. Called at the end of each read() | |
718 | * call from userspace. Drops ddebug_lock. | |
719 | */ | |
720 | static void ddebug_proc_stop(struct seq_file *m, void *p) | |
721 | { | |
722 | if (verbose) | |
4ad275e5 | 723 | pr_info("called m=%p p=%p\n", m, p); |
e9d376f0 JB |
724 | mutex_unlock(&ddebug_lock); |
725 | } | |
726 | ||
727 | static const struct seq_operations ddebug_proc_seqops = { | |
728 | .start = ddebug_proc_start, | |
729 | .next = ddebug_proc_next, | |
730 | .show = ddebug_proc_show, | |
731 | .stop = ddebug_proc_stop | |
732 | }; | |
733 | ||
734 | /* | |
07100be7 JC |
735 | * File_ops->open method for <debugfs>/dynamic_debug/control. Does |
736 | * the seq_file setup dance, and also creates an iterator to walk the | |
737 | * _ddebugs. Note that we create a seq_file always, even for O_WRONLY | |
738 | * files where it's not needed, as doing so simplifies the ->release | |
739 | * method. | |
e9d376f0 JB |
740 | */ |
741 | static int ddebug_proc_open(struct inode *inode, struct file *file) | |
742 | { | |
743 | struct ddebug_iter *iter; | |
744 | int err; | |
745 | ||
746 | if (verbose) | |
4ad275e5 | 747 | pr_info("called\n"); |
e9d376f0 JB |
748 | |
749 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
750 | if (iter == NULL) | |
751 | return -ENOMEM; | |
752 | ||
753 | err = seq_open(file, &ddebug_proc_seqops); | |
754 | if (err) { | |
755 | kfree(iter); | |
756 | return err; | |
757 | } | |
758 | ((struct seq_file *) file->private_data)->private = iter; | |
759 | return 0; | |
760 | } | |
761 | ||
762 | static const struct file_operations ddebug_proc_fops = { | |
763 | .owner = THIS_MODULE, | |
764 | .open = ddebug_proc_open, | |
765 | .read = seq_read, | |
766 | .llseek = seq_lseek, | |
767 | .release = seq_release_private, | |
768 | .write = ddebug_proc_write | |
769 | }; | |
770 | ||
771 | /* | |
772 | * Allocate a new ddebug_table for the given module | |
773 | * and add it to the global list. | |
774 | */ | |
775 | int ddebug_add_module(struct _ddebug *tab, unsigned int n, | |
776 | const char *name) | |
777 | { | |
778 | struct ddebug_table *dt; | |
779 | char *new_name; | |
780 | ||
781 | dt = kzalloc(sizeof(*dt), GFP_KERNEL); | |
782 | if (dt == NULL) | |
783 | return -ENOMEM; | |
784 | new_name = kstrdup(name, GFP_KERNEL); | |
785 | if (new_name == NULL) { | |
786 | kfree(dt); | |
787 | return -ENOMEM; | |
788 | } | |
789 | dt->mod_name = new_name; | |
790 | dt->num_ddebugs = n; | |
e9d376f0 JB |
791 | dt->ddebugs = tab; |
792 | ||
793 | mutex_lock(&ddebug_lock); | |
794 | list_add_tail(&dt->link, &ddebug_tables); | |
795 | mutex_unlock(&ddebug_lock); | |
796 | ||
797 | if (verbose) | |
4ad275e5 | 798 | pr_info("%u debug prints in module %s\n", n, dt->mod_name); |
e9d376f0 JB |
799 | return 0; |
800 | } | |
801 | EXPORT_SYMBOL_GPL(ddebug_add_module); | |
802 | ||
803 | static void ddebug_table_free(struct ddebug_table *dt) | |
804 | { | |
805 | list_del_init(&dt->link); | |
806 | kfree(dt->mod_name); | |
807 | kfree(dt); | |
808 | } | |
809 | ||
810 | /* | |
811 | * Called in response to a module being unloaded. Removes | |
812 | * any ddebug_table's which point at the module. | |
813 | */ | |
ff49d74a | 814 | int ddebug_remove_module(const char *mod_name) |
e9d376f0 JB |
815 | { |
816 | struct ddebug_table *dt, *nextdt; | |
817 | int ret = -ENOENT; | |
818 | ||
819 | if (verbose) | |
4ad275e5 | 820 | pr_info("removing module \"%s\"\n", mod_name); |
e9d376f0 JB |
821 | |
822 | mutex_lock(&ddebug_lock); | |
823 | list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) { | |
824 | if (!strcmp(dt->mod_name, mod_name)) { | |
825 | ddebug_table_free(dt); | |
826 | ret = 0; | |
827 | } | |
828 | } | |
829 | mutex_unlock(&ddebug_lock); | |
830 | return ret; | |
831 | } | |
832 | EXPORT_SYMBOL_GPL(ddebug_remove_module); | |
833 | ||
834 | static void ddebug_remove_all_tables(void) | |
835 | { | |
836 | mutex_lock(&ddebug_lock); | |
837 | while (!list_empty(&ddebug_tables)) { | |
838 | struct ddebug_table *dt = list_entry(ddebug_tables.next, | |
839 | struct ddebug_table, | |
840 | link); | |
841 | ddebug_table_free(dt); | |
842 | } | |
843 | mutex_unlock(&ddebug_lock); | |
844 | } | |
845 | ||
6a5c083d TR |
846 | static __initdata int ddebug_init_success; |
847 | ||
848 | static int __init dynamic_debug_init_debugfs(void) | |
e9d376f0 JB |
849 | { |
850 | struct dentry *dir, *file; | |
6a5c083d TR |
851 | |
852 | if (!ddebug_init_success) | |
853 | return -ENODEV; | |
e9d376f0 JB |
854 | |
855 | dir = debugfs_create_dir("dynamic_debug", NULL); | |
856 | if (!dir) | |
857 | return -ENOMEM; | |
858 | file = debugfs_create_file("control", 0644, dir, NULL, | |
859 | &ddebug_proc_fops); | |
860 | if (!file) { | |
861 | debugfs_remove(dir); | |
862 | return -ENOMEM; | |
863 | } | |
6a5c083d TR |
864 | return 0; |
865 | } | |
866 | ||
867 | static int __init dynamic_debug_init(void) | |
868 | { | |
869 | struct _ddebug *iter, *iter_start; | |
870 | const char *modname = NULL; | |
871 | int ret = 0; | |
872 | int n = 0; | |
873 | ||
e9d376f0 JB |
874 | if (__start___verbose != __stop___verbose) { |
875 | iter = __start___verbose; | |
876 | modname = iter->modname; | |
877 | iter_start = iter; | |
878 | for (; iter < __stop___verbose; iter++) { | |
879 | if (strcmp(modname, iter->modname)) { | |
880 | ret = ddebug_add_module(iter_start, n, modname); | |
881 | if (ret) | |
882 | goto out_free; | |
883 | n = 0; | |
884 | modname = iter->modname; | |
885 | iter_start = iter; | |
886 | } | |
887 | n++; | |
888 | } | |
889 | ret = ddebug_add_module(iter_start, n, modname); | |
890 | } | |
a648ec05 TR |
891 | |
892 | /* ddebug_query boot param got passed -> set it up */ | |
893 | if (ddebug_setup_string[0] != '\0') { | |
894 | ret = ddebug_exec_query(ddebug_setup_string); | |
895 | if (ret) | |
4ad275e5 JP |
896 | pr_warn("Invalid ddebug boot param %s", |
897 | ddebug_setup_string); | |
a648ec05 TR |
898 | else |
899 | pr_info("ddebug initialized with string %s", | |
900 | ddebug_setup_string); | |
901 | } | |
902 | ||
e9d376f0 | 903 | out_free: |
6a5c083d | 904 | if (ret) |
e9d376f0 | 905 | ddebug_remove_all_tables(); |
6a5c083d TR |
906 | else |
907 | ddebug_init_success = 1; | |
e9d376f0 JB |
908 | return 0; |
909 | } | |
6a5c083d TR |
910 | /* Allow early initialization for boot messages via boot param */ |
911 | arch_initcall(dynamic_debug_init); | |
912 | /* Debugfs setup must be done later */ | |
913 | module_init(dynamic_debug_init_debugfs); |