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/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/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