1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * S/390 debug facility
4 *
5 * Copyright IBM Corp. 1999, 2020
6 */
7 #ifndef _ASM_S390_DEBUG_H
8 #define _ASM_S390_DEBUG_H
9
10 #include <linux/string.h>
11 #include <linux/spinlock.h>
12 #include <linux/kernel.h>
13 #include <linux/time.h>
14 #include <linux/refcount.h>
15 #include <linux/fs.h>
16 #include <linux/init.h>
17
18 #define DEBUG_MAX_LEVEL 6 /* debug levels range from 0 to 6 */
19 #define DEBUG_OFF_LEVEL -1 /* level where debug is switched off */
20 #define DEBUG_FLUSH_ALL -1 /* parameter to flush all areas */
21 #define DEBUG_MAX_VIEWS 10 /* max number of views in proc fs */
22 #define DEBUG_MAX_NAME_LEN 64 /* max length for a debugfs file name */
23 #define DEBUG_DEFAULT_LEVEL 3 /* initial debug level */
24
25 #define DEBUG_DIR_ROOT "s390dbf" /* name of debug root directory in proc fs */
26
27 #define DEBUG_DATA(entry) (char *)(entry + 1) /* data is stored behind */
28 /* the entry information */
29
30 #define __DEBUG_FEATURE_VERSION 3 /* version of debug feature */
31
32 struct __debug_entry {
33 unsigned long clock : 60;
34 unsigned long exception : 1;
35 unsigned long level : 3;
36 void *caller;
37 unsigned short cpu;
38 } __packed;
39
40 typedef struct __debug_entry debug_entry_t;
41
42 struct debug_view;
43
44 typedef struct debug_info {
45 struct debug_info *next;
46 struct debug_info *prev;
47 refcount_t ref_count;
48 spinlock_t lock;
49 int level;
50 int nr_areas;
51 int pages_per_area;
52 int buf_size;
53 int entry_size;
54 debug_entry_t ***areas;
55 int active_area;
56 int *active_pages;
57 int *active_entries;
58 struct dentry *debugfs_root_entry;
59 struct dentry *debugfs_entries[DEBUG_MAX_VIEWS];
60 struct debug_view *views[DEBUG_MAX_VIEWS];
61 char name[DEBUG_MAX_NAME_LEN];
62 umode_t mode;
63 } debug_info_t;
64
65 typedef int (debug_header_proc_t) (debug_info_t *id,
66 struct debug_view *view,
67 int area,
68 debug_entry_t *entry,
69 char *out_buf);
70
71 typedef int (debug_format_proc_t) (debug_info_t *id,
72 struct debug_view *view, char *out_buf,
73 const char *in_buf);
74 typedef int (debug_prolog_proc_t) (debug_info_t *id,
75 struct debug_view *view,
76 char *out_buf);
77 typedef int (debug_input_proc_t) (debug_info_t *id,
78 struct debug_view *view,
79 struct file *file,
80 const char __user *user_buf,
81 size_t in_buf_size, loff_t *offset);
82
83 int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
84 int area, debug_entry_t *entry, char *out_buf);
85
86 struct debug_view {
87 char name[DEBUG_MAX_NAME_LEN];
88 debug_prolog_proc_t *prolog_proc;
89 debug_header_proc_t *header_proc;
90 debug_format_proc_t *format_proc;
91 debug_input_proc_t *input_proc;
92 void *private_data;
93 };
94
95 extern struct debug_view debug_hex_ascii_view;
96 extern struct debug_view debug_sprintf_view;
97
98 /* do NOT use the _common functions */
99
100 debug_entry_t *debug_event_common(debug_info_t *id, int level,
101 const void *data, int length);
102
103 debug_entry_t *debug_exception_common(debug_info_t *id, int level,
104 const void *data, int length);
105
106 /* Debug Feature API: */
107
108 debug_info_t *debug_register(const char *name, int pages, int nr_areas,
109 int buf_size);
110
111 debug_info_t *debug_register_mode(const char *name, int pages, int nr_areas,
112 int buf_size, umode_t mode, uid_t uid,
113 gid_t gid);
114
115 void debug_unregister(debug_info_t *id);
116
117 void debug_set_level(debug_info_t *id, int new_level);
118
119 void debug_set_critical(void);
120
121 void debug_stop_all(void);
122
123 /**
124 * debug_level_enabled() - Returns true if debug events for the specified
125 * level would be logged. Otherwise returns false.
126 *
127 * @id: handle for debug log
128 * @level: debug level
129 *
130 * Return:
131 * - %true if level is less or equal to the current debug level.
132 */
133 static inline bool debug_level_enabled(debug_info_t *id, int level)
134 {
135 return level <= id->level;
136 }
137
138 /**
139 * debug_event() - writes binary debug entry to active debug area
140 * (if level <= actual debug level)
141 *
142 * @id: handle for debug log
143 * @level: debug level
144 * @data: pointer to data for debug entry
145 * @length: length of data in bytes
146 *
147 * Return:
148 * - Address of written debug entry
149 * - %NULL if error
150 */
151 static inline debug_entry_t *debug_event(debug_info_t *id, int level,
152 void *data, int length)
153 {
154 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
155 return NULL;
156 return debug_event_common(id, level, data, length);
157 }
158
159 /**
160 * debug_int_event() - writes unsigned integer debug entry to active debug area
161 * (if level <= actual debug level)
162 *
163 * @id: handle for debug log
164 * @level: debug level
165 * @tag: integer value for debug entry
166 *
167 * Return:
168 * - Address of written debug entry
169 * - %NULL if error
170 */
171 static inline debug_entry_t *debug_int_event(debug_info_t *id, int level,
172 unsigned int tag)
173 {
174 unsigned int t = tag;
175
176 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
177 return NULL;
178 return debug_event_common(id, level, &t, sizeof(unsigned int));
179 }
180
181 /**
182 * debug_long_event() - writes unsigned long debug entry to active debug area
183 * (if level <= actual debug level)
184 *
185 * @id: handle for debug log
186 * @level: debug level
187 * @tag: long integer value for debug entry
188 *
189 * Return:
190 * - Address of written debug entry
191 * - %NULL if error
192 */
193 static inline debug_entry_t *debug_long_event(debug_info_t *id, int level,
194 unsigned long tag)
195 {
196 unsigned long t = tag;
197
198 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
199 return NULL;
200 return debug_event_common(id, level, &t, sizeof(unsigned long));
201 }
202
203 /**
204 * debug_text_event() - writes string debug entry in ascii format to active
205 * debug area (if level <= actual debug level)
206 *
207 * @id: handle for debug log
208 * @level: debug level
209 * @txt: string for debug entry
210 *
211 * Return:
212 * - Address of written debug entry
213 * - %NULL if error
214 */
215 static inline debug_entry_t *debug_text_event(debug_info_t *id, int level,
216 const char *txt)
217 {
218 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
219 return NULL;
220 return debug_event_common(id, level, txt, strlen(txt));
221 }
222
223 /*
224 * IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are
225 * stored in the s390dbf. See Documentation/arch/s390/s390dbf.rst for more details!
226 */
227 extern debug_entry_t *
228 __debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
229 __attribute__ ((format(printf, 3, 4)));
230
231 /**
232 * debug_sprintf_event() - writes debug entry with format string
233 * and varargs (longs) to active debug area
234 * (if level $<=$ actual debug level).
235 *
236 * @_id: handle for debug log
237 * @_level: debug level
238 * @_fmt: format string for debug entry
239 * @...: varargs used as in sprintf()
240 *
241 * Return:
242 * - Address of written debug entry
243 * - %NULL if error
244 *
245 * floats and long long datatypes cannot be used as varargs.
246 */
247 #define debug_sprintf_event(_id, _level, _fmt, ...) \
248 ({ \
249 debug_entry_t *__ret; \
250 debug_info_t *__id = _id; \
251 int __level = _level; \
252 \
253 if ((!__id) || (__level > __id->level)) \
254 __ret = NULL; \
255 else \
256 __ret = __debug_sprintf_event(__id, __level, \
257 _fmt, ## __VA_ARGS__); \
258 __ret; \
259 })
260
261 /**
262 * debug_exception() - writes binary debug entry to active debug area
263 * (if level <= actual debug level)
264 * and switches to next debug area
265 *
266 * @id: handle for debug log
267 * @level: debug level
268 * @data: pointer to data for debug entry
269 * @length: length of data in bytes
270 *
271 * Return:
272 * - Address of written debug entry
273 * - %NULL if error
274 */
275 static inline debug_entry_t *debug_exception(debug_info_t *id, int level,
276 void *data, int length)
277 {
278 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
279 return NULL;
280 return debug_exception_common(id, level, data, length);
281 }
282
283 /**
284 * debug_int_exception() - writes unsigned int debug entry to active debug area
285 * (if level <= actual debug level)
286 * and switches to next debug area
287 *
288 * @id: handle for debug log
289 * @level: debug level
290 * @tag: integer value for debug entry
291 *
292 * Return:
293 * - Address of written debug entry
294 * - %NULL if error
295 */
296 static inline debug_entry_t *debug_int_exception(debug_info_t *id, int level,
297 unsigned int tag)
298 {
299 unsigned int t = tag;
300
301 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
302 return NULL;
303 return debug_exception_common(id, level, &t, sizeof(unsigned int));
304 }
305
306 /**
307 * debug_long_exception() - writes long debug entry to active debug area
308 * (if level <= actual debug level)
309 * and switches to next debug area
310 *
311 * @id: handle for debug log
312 * @level: debug level
313 * @tag: long integer value for debug entry
314 *
315 * Return:
316 * - Address of written debug entry
317 * - %NULL if error
318 */
319 static inline debug_entry_t *debug_long_exception (debug_info_t *id, int level,
320 unsigned long tag)
321 {
322 unsigned long t = tag;
323
324 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
325 return NULL;
326 return debug_exception_common(id, level, &t, sizeof(unsigned long));
327 }
328
329 /**
330 * debug_text_exception() - writes string debug entry in ascii format to active
331 * debug area (if level <= actual debug level)
332 * and switches to next debug area
333 * area
334 *
335 * @id: handle for debug log
336 * @level: debug level
337 * @txt: string for debug entry
338 *
339 * Return:
340 * - Address of written debug entry
341 * - %NULL if error
342 */
343 static inline debug_entry_t *debug_text_exception(debug_info_t *id, int level,
344 const char *txt)
345 {
346 if ((!id) || (level > id->level) || (id->pages_per_area == 0))
347 return NULL;
348 return debug_exception_common(id, level, txt, strlen(txt));
349 }
350
351 /*
352 * IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are
353 * stored in the s390dbf. See Documentation/arch/s390/s390dbf.rst for more details!
354 */
355 extern debug_entry_t *
356 __debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
357 __attribute__ ((format(printf, 3, 4)));
358
359
360 /**
361 * debug_sprintf_exception() - writes debug entry with format string and
362 * varargs (longs) to active debug area
363 * (if level <= actual debug level)
364 * and switches to next debug area.
365 *
366 * @_id: handle for debug log
367 * @_level: debug level
368 * @_fmt: format string for debug entry
369 * @...: varargs used as in sprintf()
370 *
371 * Return:
372 * - Address of written debug entry
373 * - %NULL if error
374 *
375 * floats and long long datatypes cannot be used as varargs.
376 */
377 #define debug_sprintf_exception(_id, _level, _fmt, ...) \
378 ({ \
379 debug_entry_t *__ret; \
380 debug_info_t *__id = _id; \
381 int __level = _level; \
382 \
383 if ((!__id) || (__level > __id->level)) \
384 __ret = NULL; \
385 else \
386 __ret = __debug_sprintf_exception(__id, __level, \
387 _fmt, ## __VA_ARGS__);\
388 __ret; \
389 })
390
391 int debug_register_view(debug_info_t *id, struct debug_view *view);
392
393 int debug_unregister_view(debug_info_t *id, struct debug_view *view);
394
395 #ifndef MODULE
396
397 /*
398 * Note: Initial page and area numbers must be fixed to allow static
399 * initialization. This enables very early tracing. Changes to these values
400 * must be reflected in __DEFINE_STATIC_AREA.
401 */
402 #define EARLY_PAGES 8
403 #define EARLY_AREAS 1
404
405 #define VNAME(var, suffix) __##var##_##suffix
406
407 /*
408 * Define static areas for early trace data. During boot debug_register_static()
409 * will replace these with dynamically allocated areas to allow custom page and
410 * area sizes, and dynamic resizing.
411 */
412 #define __DEFINE_STATIC_AREA(var) \
413 static char VNAME(var, data)[EARLY_PAGES][PAGE_SIZE] __initdata; \
414 static debug_entry_t *VNAME(var, pages)[EARLY_PAGES] __initdata = { \
415 (debug_entry_t *)VNAME(var, data)[0], \
416 (debug_entry_t *)VNAME(var, data)[1], \
417 (debug_entry_t *)VNAME(var, data)[2], \
418 (debug_entry_t *)VNAME(var, data)[3], \
419 (debug_entry_t *)VNAME(var, data)[4], \
420 (debug_entry_t *)VNAME(var, data)[5], \
421 (debug_entry_t *)VNAME(var, data)[6], \
422 (debug_entry_t *)VNAME(var, data)[7], \
423 }; \
424 static debug_entry_t **VNAME(var, areas)[EARLY_AREAS] __initdata = { \
425 (debug_entry_t **)VNAME(var, pages), \
426 }; \
427 static int VNAME(var, active_pages)[EARLY_AREAS] __initdata; \
428 static int VNAME(var, active_entries)[EARLY_AREAS] __initdata
429
430 #define __DEBUG_INFO_INIT(var, _name, _buf_size) { \
431 .next = NULL, \
432 .prev = NULL, \
433 .ref_count = REFCOUNT_INIT(1), \
434 .lock = __SPIN_LOCK_UNLOCKED(var.lock), \
435 .level = DEBUG_DEFAULT_LEVEL, \
436 .nr_areas = EARLY_AREAS, \
437 .pages_per_area = EARLY_PAGES, \
438 .buf_size = (_buf_size), \
439 .entry_size = sizeof(debug_entry_t) + (_buf_size), \
440 .areas = VNAME(var, areas), \
441 .active_area = 0, \
442 .active_pages = VNAME(var, active_pages), \
443 .active_entries = VNAME(var, active_entries), \
444 .debugfs_root_entry = NULL, \
445 .debugfs_entries = { NULL }, \
446 .views = { NULL }, \
447 .name = (_name), \
448 .mode = 0600, \
449 }
450
451 #define __REGISTER_STATIC_DEBUG_INFO(var, name, pages, areas, view) \
452 static int __init VNAME(var, reg)(void) \
453 { \
454 debug_register_static(&var, (pages), (areas)); \
455 debug_register_view(&var, (view)); \
456 return 0; \
457 } \
458 arch_initcall(VNAME(var, reg))
459
460 /**
461 * DEFINE_STATIC_DEBUG_INFO - Define static debug_info_t
462 *
463 * @var: Name of debug_info_t variable
464 * @name: Name of debug log (e.g. used for debugfs entry)
465 * @pages: Number of pages per area
466 * @nr_areas: Number of debug areas
467 * @buf_size: Size of data area in each debug entry
468 * @view: Pointer to debug view struct
469 *
470 * Define a static debug_info_t for early tracing. The associated debugfs log
471 * is automatically registered with the specified debug view.
472 *
473 * Important: Users of this macro must not call any of the
474 * debug_register/_unregister() functions for this debug_info_t!
475 *
476 * Note: Tracing will start with a fixed number of initial pages and areas.
477 * The debug area will be changed to use the specified numbers during
478 * arch_initcall.
479 */
480 #define DEFINE_STATIC_DEBUG_INFO(var, name, pages, nr_areas, buf_size, view) \
481 __DEFINE_STATIC_AREA(var); \
482 static debug_info_t __refdata var = \
483 __DEBUG_INFO_INIT(var, (name), (buf_size)); \
484 __REGISTER_STATIC_DEBUG_INFO(var, name, pages, nr_areas, view)
485
486 void debug_register_static(debug_info_t *id, int pages_per_area, int nr_areas);
487
488 #endif /* MODULE */
489
490 #endif /* _ASM_S390_DEBUG_H */
491
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