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, size_t out_buf_size); 70 71 typedef int (debug_format_proc_t) (debug_info_t *id, 72 struct debug_view *view, char *out_buf, 73 size_t out_buf_size, 74 const char *in_buf); 75 typedef int (debug_prolog_proc_t) (debug_info_t *id, 76 struct debug_view *view, 77 char *out_buf, size_t out_buf_size); 78 typedef int (debug_input_proc_t) (debug_info_t *id, 79 struct debug_view *view, 80 struct file *file, 81 const char __user *user_buf, 82 size_t in_buf_size, loff_t *offset); 83 84 int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view, 85 int area, debug_entry_t *entry, 86 char *out_buf, size_t out_buf_size); 87 88 struct debug_view { 89 char name[DEBUG_MAX_NAME_LEN]; 90 debug_prolog_proc_t *prolog_proc; 91 debug_header_proc_t *header_proc; 92 debug_format_proc_t *format_proc; 93 debug_input_proc_t *input_proc; 94 void *private_data; 95 }; 96 97 extern struct debug_view debug_hex_ascii_view; 98 extern struct debug_view debug_sprintf_view; 99 100 /* do NOT use the _common functions */ 101 102 debug_entry_t *debug_event_common(debug_info_t *id, int level, 103 const void *data, int length); 104 105 debug_entry_t *debug_exception_common(debug_info_t *id, int level, 106 const void *data, int length); 107 108 /* Debug Feature API: */ 109 110 debug_info_t *debug_register(const char *name, int pages, int nr_areas, 111 int buf_size); 112 113 debug_info_t *debug_register_mode(const char *name, int pages, int nr_areas, 114 int buf_size, umode_t mode, uid_t uid, 115 gid_t gid); 116 117 void debug_unregister(debug_info_t *id); 118 119 void debug_set_level(debug_info_t *id, int new_level); 120 121 void debug_set_critical(void); 122 123 void debug_stop_all(void); 124 125 /** 126 * debug_level_enabled() - Returns true if debug events for the specified 127 * level would be logged. Otherwise returns false. 128 * 129 * @id: handle for debug log 130 * @level: debug level 131 * 132 * Return: 133 * - %true if level is less or equal to the current debug level. 134 */ 135 static inline bool debug_level_enabled(debug_info_t *id, int level) 136 { 137 return level <= id->level; 138 } 139 140 /** 141 * debug_event() - writes binary debug entry to active debug area 142 * (if level <= actual debug level) 143 * 144 * @id: handle for debug log 145 * @level: debug level 146 * @data: pointer to data for debug entry 147 * @length: length of data in bytes 148 * 149 * Return: 150 * - Address of written debug entry 151 * - %NULL if error 152 */ 153 static inline debug_entry_t *debug_event(debug_info_t *id, int level, 154 void *data, int length) 155 { 156 if ((!id) || (level > id->level) || (id->pages_per_area == 0)) 157 return NULL; 158 return debug_event_common(id, level, data, length); 159 } 160 161 /** 162 * debug_int_event() - writes unsigned integer debug entry to active debug area 163 * (if level <= actual debug level) 164 * 165 * @id: handle for debug log 166 * @level: debug level 167 * @tag: integer value for debug entry 168 * 169 * Return: 170 * - Address of written debug entry 171 * - %NULL if error 172 */ 173 static inline debug_entry_t *debug_int_event(debug_info_t *id, int level, 174 unsigned int tag) 175 { 176 unsigned int t = tag; 177 178 if ((!id) || (level > id->level) || (id->pages_per_area == 0)) 179 return NULL; 180 return debug_event_common(id, level, &t, sizeof(unsigned int)); 181 } 182 183 /** 184 * debug_long_event() - writes unsigned long debug entry to active debug area 185 * (if level <= actual debug level) 186 * 187 * @id: handle for debug log 188 * @level: debug level 189 * @tag: long integer value for debug entry 190 * 191 * Return: 192 * - Address of written debug entry 193 * - %NULL if error 194 */ 195 static inline debug_entry_t *debug_long_event(debug_info_t *id, int level, 196 unsigned long tag) 197 { 198 unsigned long t = tag; 199 200 if ((!id) || (level > id->level) || (id->pages_per_area == 0)) 201 return NULL; 202 return debug_event_common(id, level, &t, sizeof(unsigned long)); 203 } 204 205 /** 206 * debug_text_event() - writes string debug entry in ascii format to active 207 * debug area (if level <= actual debug level) 208 * 209 * @id: handle for debug log 210 * @level: debug level 211 * @txt: string for debug entry 212 * 213 * Return: 214 * - Address of written debug entry 215 * - %NULL if error 216 */ 217 static inline debug_entry_t *debug_text_event(debug_info_t *id, int level, 218 const char *txt) 219 { 220 if ((!id) || (level > id->level) || (id->pages_per_area == 0)) 221 return NULL; 222 return debug_event_common(id, level, txt, strlen(txt)); 223 } 224 225 /* 226 * IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are 227 * stored in the s390dbf. See Documentation/arch/s390/s390dbf.rst for more details! 228 */ 229 extern debug_entry_t * 230 __debug_sprintf_event(debug_info_t *id, int level, char *string, ...) 231 __attribute__ ((format(printf, 3, 4))); 232 233 /** 234 * debug_sprintf_event() - writes debug entry with format string 235 * and varargs (longs) to active debug area 236 * (if level $<=$ actual debug level). 237 * 238 * @_id: handle for debug log 239 * @_level: debug level 240 * @_fmt: format string for debug entry 241 * @...: varargs used as in sprintf() 242 * 243 * Return: 244 * - Address of written debug entry 245 * - %NULL if error 246 * 247 * floats and long long datatypes cannot be used as varargs. 248 */ 249 #define debug_sprintf_event(_id, _level, _fmt, ...) \ 250 ({ \ 251 debug_entry_t *__ret; \ 252 debug_info_t *__id = _id; \ 253 int __level = _level; \ 254 \ 255 if ((!__id) || (__level > __id->level)) \ 256 __ret = NULL; \ 257 else \ 258 __ret = __debug_sprintf_event(__id, __level, \ 259 _fmt, ## __VA_ARGS__); \ 260 __ret; \ 261 }) 262 263 /** 264 * debug_exception() - writes binary debug entry to active debug area 265 * (if level <= actual debug level) 266 * and switches to next debug area 267 * 268 * @id: handle for debug log 269 * @level: debug level 270 * @data: pointer to data for debug entry 271 * @length: length of data in bytes 272 * 273 * Return: 274 * - Address of written debug entry 275 * - %NULL if error 276 */ 277 static inline debug_entry_t *debug_exception(debug_info_t *id, int level, 278 void *data, int length) 279 { 280 if ((!id) || (level > id->level) || (id->pages_per_area == 0)) 281 return NULL; 282 return debug_exception_common(id, level, data, length); 283 } 284 285 /** 286 * debug_int_exception() - writes unsigned int debug entry to active debug area 287 * (if level <= actual debug level) 288 * and switches to next debug area 289 * 290 * @id: handle for debug log 291 * @level: debug level 292 * @tag: integer value for debug entry 293 * 294 * Return: 295 * - Address of written debug entry 296 * - %NULL if error 297 */ 298 static inline debug_entry_t *debug_int_exception(debug_info_t *id, int level, 299 unsigned int tag) 300 { 301 unsigned int t = tag; 302 303 if ((!id) || (level > id->level) || (id->pages_per_area == 0)) 304 return NULL; 305 return debug_exception_common(id, level, &t, sizeof(unsigned int)); 306 } 307 308 /** 309 * debug_long_exception() - writes long debug entry to active debug area 310 * (if level <= actual debug level) 311 * and switches to next debug area 312 * 313 * @id: handle for debug log 314 * @level: debug level 315 * @tag: long integer value for debug entry 316 * 317 * Return: 318 * - Address of written debug entry 319 * - %NULL if error 320 */ 321 static inline debug_entry_t *debug_long_exception (debug_info_t *id, int level, 322 unsigned long tag) 323 { 324 unsigned long t = tag; 325 326 if ((!id) || (level > id->level) || (id->pages_per_area == 0)) 327 return NULL; 328 return debug_exception_common(id, level, &t, sizeof(unsigned long)); 329 } 330 331 /** 332 * debug_text_exception() - writes string debug entry in ascii format to active 333 * debug area (if level <= actual debug level) 334 * and switches to next debug area 335 * area 336 * 337 * @id: handle for debug log 338 * @level: debug level 339 * @txt: string for debug entry 340 * 341 * Return: 342 * - Address of written debug entry 343 * - %NULL if error 344 */ 345 static inline debug_entry_t *debug_text_exception(debug_info_t *id, int level, 346 const char *txt) 347 { 348 if ((!id) || (level > id->level) || (id->pages_per_area == 0)) 349 return NULL; 350 return debug_exception_common(id, level, txt, strlen(txt)); 351 } 352 353 /* 354 * IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are 355 * stored in the s390dbf. See Documentation/arch/s390/s390dbf.rst for more details! 356 */ 357 extern debug_entry_t * 358 __debug_sprintf_exception(debug_info_t *id, int level, char *string, ...) 359 __attribute__ ((format(printf, 3, 4))); 360 361 362 /** 363 * debug_sprintf_exception() - writes debug entry with format string and 364 * varargs (longs) to active debug area 365 * (if level <= actual debug level) 366 * and switches to next debug area. 367 * 368 * @_id: handle for debug log 369 * @_level: debug level 370 * @_fmt: format string for debug entry 371 * @...: varargs used as in sprintf() 372 * 373 * Return: 374 * - Address of written debug entry 375 * - %NULL if error 376 * 377 * floats and long long datatypes cannot be used as varargs. 378 */ 379 #define debug_sprintf_exception(_id, _level, _fmt, ...) \ 380 ({ \ 381 debug_entry_t *__ret; \ 382 debug_info_t *__id = _id; \ 383 int __level = _level; \ 384 \ 385 if ((!__id) || (__level > __id->level)) \ 386 __ret = NULL; \ 387 else \ 388 __ret = __debug_sprintf_exception(__id, __level, \ 389 _fmt, ## __VA_ARGS__);\ 390 __ret; \ 391 }) 392 393 int debug_register_view(debug_info_t *id, struct debug_view *view); 394 395 int debug_unregister_view(debug_info_t *id, struct debug_view *view); 396 397 #ifndef MODULE 398 399 /* 400 * Note: Initial page and area numbers must be fixed to allow static 401 * initialization. This enables very early tracing. Changes to these values 402 * must be reflected in __DEFINE_STATIC_AREA. 403 */ 404 #define EARLY_PAGES 8 405 #define EARLY_AREAS 1 406 407 #define VNAME(var, suffix) __##var##_##suffix 408 409 /* 410 * Define static areas for early trace data. During boot debug_register_static() 411 * will replace these with dynamically allocated areas to allow custom page and 412 * area sizes, and dynamic resizing. 413 */ 414 #define __DEFINE_STATIC_AREA(var) \ 415 static char VNAME(var, data)[EARLY_PAGES][PAGE_SIZE] __initdata; \ 416 static debug_entry_t *VNAME(var, pages)[EARLY_PAGES] __initdata = { \ 417 (debug_entry_t *)VNAME(var, data)[0], \ 418 (debug_entry_t *)VNAME(var, data)[1], \ 419 (debug_entry_t *)VNAME(var, data)[2], \ 420 (debug_entry_t *)VNAME(var, data)[3], \ 421 (debug_entry_t *)VNAME(var, data)[4], \ 422 (debug_entry_t *)VNAME(var, data)[5], \ 423 (debug_entry_t *)VNAME(var, data)[6], \ 424 (debug_entry_t *)VNAME(var, data)[7], \ 425 }; \ 426 static debug_entry_t **VNAME(var, areas)[EARLY_AREAS] __initdata = { \ 427 (debug_entry_t **)VNAME(var, pages), \ 428 }; \ 429 static int VNAME(var, active_pages)[EARLY_AREAS] __initdata; \ 430 static int VNAME(var, active_entries)[EARLY_AREAS] __initdata 431 432 #define __DEBUG_INFO_INIT(var, _name, _buf_size) { \ 433 .next = NULL, \ 434 .prev = NULL, \ 435 .ref_count = REFCOUNT_INIT(1), \ 436 .lock = __SPIN_LOCK_UNLOCKED(var.lock), \ 437 .level = DEBUG_DEFAULT_LEVEL, \ 438 .nr_areas = EARLY_AREAS, \ 439 .pages_per_area = EARLY_PAGES, \ 440 .buf_size = (_buf_size), \ 441 .entry_size = sizeof(debug_entry_t) + (_buf_size), \ 442 .areas = VNAME(var, areas), \ 443 .active_area = 0, \ 444 .active_pages = VNAME(var, active_pages), \ 445 .active_entries = VNAME(var, active_entries), \ 446 .debugfs_root_entry = NULL, \ 447 .debugfs_entries = { NULL }, \ 448 .views = { NULL }, \ 449 .name = (_name), \ 450 .mode = 0600, \ 451 } 452 453 #define __REGISTER_STATIC_DEBUG_INFO(var, name, pages, areas, view) \ 454 static int __init VNAME(var, reg)(void) \ 455 { \ 456 debug_register_static(&var, (pages), (areas)); \ 457 debug_register_view(&var, (view)); \ 458 return 0; \ 459 } \ 460 arch_initcall(VNAME(var, reg)) 461 462 /** 463 * DEFINE_STATIC_DEBUG_INFO - Define static debug_info_t 464 * 465 * @var: Name of debug_info_t variable 466 * @name: Name of debug log (e.g. used for debugfs entry) 467 * @pages: Number of pages per area 468 * @nr_areas: Number of debug areas 469 * @buf_size: Size of data area in each debug entry 470 * @view: Pointer to debug view struct 471 * 472 * Define a static debug_info_t for early tracing. The associated debugfs log 473 * is automatically registered with the specified debug view. 474 * 475 * Important: Users of this macro must not call any of the 476 * debug_register/_unregister() functions for this debug_info_t! 477 * 478 * Note: Tracing will start with a fixed number of initial pages and areas. 479 * The debug area will be changed to use the specified numbers during 480 * arch_initcall. 481 */ 482 #define DEFINE_STATIC_DEBUG_INFO(var, name, pages, nr_areas, buf_size, view) \ 483 __DEFINE_STATIC_AREA(var); \ 484 static debug_info_t __refdata var = \ 485 __DEBUG_INFO_INIT(var, (name), (buf_size)); \ 486 __REGISTER_STATIC_DEBUG_INFO(var, name, pages, nr_areas, view) 487 488 void debug_register_static(debug_info_t *id, int pages_per_area, int nr_areas); 489 490 #endif /* MODULE */ 491 492 #endif /* _ASM_S390_DEBUG_H */ 493