1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Ftrace header. For implementation details beyond the random comments 4 * scattered below, see: Documentation/trace/ftrace-design.rst 5 */ 6 7 #ifndef _LINUX_FTRACE_H 8 #define _LINUX_FTRACE_H 9 10 #include <linux/trace_clock.h> 11 #include <linux/kallsyms.h> 12 #include <linux/linkage.h> 13 #include <linux/bitops.h> 14 #include <linux/ptrace.h> 15 #include <linux/ktime.h> 16 #include <linux/sched.h> 17 #include <linux/types.h> 18 #include <linux/init.h> 19 #include <linux/fs.h> 20 21 #include <asm/ftrace.h> 22 23 /* 24 * If the arch supports passing the variable contents of 25 * function_trace_op as the third parameter back from the 26 * mcount call, then the arch should define this as 1. 27 */ 28 #ifndef ARCH_SUPPORTS_FTRACE_OPS 29 #define ARCH_SUPPORTS_FTRACE_OPS 0 30 #endif 31 32 /* 33 * If the arch's mcount caller does not support all of ftrace's 34 * features, then it must call an indirect function that 35 * does. Or at least does enough to prevent any unwelcomed side effects. 36 */ 37 #if !ARCH_SUPPORTS_FTRACE_OPS 38 # define FTRACE_FORCE_LIST_FUNC 1 39 #else 40 # define FTRACE_FORCE_LIST_FUNC 0 41 #endif 42 43 /* Main tracing buffer and events set up */ 44 #ifdef CONFIG_TRACING 45 void trace_init(void); 46 void early_trace_init(void); 47 #else 48 static inline void trace_init(void) { } 49 static inline void early_trace_init(void) { } 50 #endif 51 52 struct module; 53 struct ftrace_hash; 54 55 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \ 56 defined(CONFIG_DYNAMIC_FTRACE) 57 const char * 58 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 59 unsigned long *off, char **modname, char *sym); 60 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 61 char *type, char *name, 62 char *module_name, int *exported); 63 #else 64 static inline const char * 65 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 66 unsigned long *off, char **modname, char *sym) 67 { 68 return NULL; 69 } 70 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 71 char *type, char *name, 72 char *module_name, int *exported) 73 { 74 return -1; 75 } 76 #endif 77 78 79 #ifdef CONFIG_FUNCTION_TRACER 80 81 extern int ftrace_enabled; 82 extern int 83 ftrace_enable_sysctl(struct ctl_table *table, int write, 84 void __user *buffer, size_t *lenp, 85 loff_t *ppos); 86 87 struct ftrace_ops; 88 89 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 90 struct ftrace_ops *op, struct pt_regs *regs); 91 92 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 93 94 /* 95 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 96 * set in the flags member. 97 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION_SAFE, STUB and 98 * IPMODIFY are a kind of attribute flags which can be set only before 99 * registering the ftrace_ops, and can not be modified while registered. 100 * Changing those attribute flags after registering ftrace_ops will 101 * cause unexpected results. 102 * 103 * ENABLED - set/unset when ftrace_ops is registered/unregistered 104 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 105 * allocated ftrace_ops which need special care 106 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 107 * and passed to the callback. If this flag is set, but the 108 * architecture does not support passing regs 109 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 110 * ftrace_ops will fail to register, unless the next flag 111 * is set. 112 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 113 * handler can handle an arch that does not save regs 114 * (the handler tests if regs == NULL), then it can set 115 * this flag instead. It will not fail registering the ftrace_ops 116 * but, the regs field will be NULL if the arch does not support 117 * passing regs to the handler. 118 * Note, if this flag is set, the SAVE_REGS flag will automatically 119 * get set upon registering the ftrace_ops, if the arch supports it. 120 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure 121 * that the call back has its own recursion protection. If it does 122 * not set this, then the ftrace infrastructure will add recursion 123 * protection for the caller. 124 * STUB - The ftrace_ops is just a place holder. 125 * INITIALIZED - The ftrace_ops has already been initialized (first use time 126 * register_ftrace_function() is called, it will initialized the ops) 127 * DELETED - The ops are being deleted, do not let them be registered again. 128 * ADDING - The ops is in the process of being added. 129 * REMOVING - The ops is in the process of being removed. 130 * MODIFYING - The ops is in the process of changing its filter functions. 131 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 132 * The arch specific code sets this flag when it allocated a 133 * trampoline. This lets the arch know that it can update the 134 * trampoline in case the callback function changes. 135 * The ftrace_ops trampoline can be set by the ftrace users, and 136 * in such cases the arch must not modify it. Only the arch ftrace 137 * core code should set this flag. 138 * IPMODIFY - The ops can modify the IP register. This can only be set with 139 * SAVE_REGS. If another ops with this flag set is already registered 140 * for any of the functions that this ops will be registered for, then 141 * this ops will fail to register or set_filter_ip. 142 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 143 * RCU - Set when the ops can only be called when RCU is watching. 144 * TRACE_ARRAY - The ops->private points to a trace_array descriptor. 145 */ 146 enum { 147 FTRACE_OPS_FL_ENABLED = 1 << 0, 148 FTRACE_OPS_FL_DYNAMIC = 1 << 1, 149 FTRACE_OPS_FL_SAVE_REGS = 1 << 2, 150 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 3, 151 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 4, 152 FTRACE_OPS_FL_STUB = 1 << 5, 153 FTRACE_OPS_FL_INITIALIZED = 1 << 6, 154 FTRACE_OPS_FL_DELETED = 1 << 7, 155 FTRACE_OPS_FL_ADDING = 1 << 8, 156 FTRACE_OPS_FL_REMOVING = 1 << 9, 157 FTRACE_OPS_FL_MODIFYING = 1 << 10, 158 FTRACE_OPS_FL_ALLOC_TRAMP = 1 << 11, 159 FTRACE_OPS_FL_IPMODIFY = 1 << 12, 160 FTRACE_OPS_FL_PID = 1 << 13, 161 FTRACE_OPS_FL_RCU = 1 << 14, 162 FTRACE_OPS_FL_TRACE_ARRAY = 1 << 15, 163 }; 164 165 #ifdef CONFIG_DYNAMIC_FTRACE 166 /* The hash used to know what functions callbacks trace */ 167 struct ftrace_ops_hash { 168 struct ftrace_hash __rcu *notrace_hash; 169 struct ftrace_hash __rcu *filter_hash; 170 struct mutex regex_lock; 171 }; 172 173 void ftrace_free_init_mem(void); 174 void ftrace_free_mem(struct module *mod, void *start, void *end); 175 #else 176 static inline void ftrace_free_init_mem(void) { } 177 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 178 #endif 179 180 /* 181 * Note, ftrace_ops can be referenced outside of RCU protection, unless 182 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel 183 * core data, the unregistering of it will perform a scheduling on all CPUs 184 * to make sure that there are no more users. Depending on the load of the 185 * system that may take a bit of time. 186 * 187 * Any private data added must also take care not to be freed and if private 188 * data is added to a ftrace_ops that is in core code, the user of the 189 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 190 */ 191 struct ftrace_ops { 192 ftrace_func_t func; 193 struct ftrace_ops __rcu *next; 194 unsigned long flags; 195 void *private; 196 ftrace_func_t saved_func; 197 #ifdef CONFIG_DYNAMIC_FTRACE 198 struct ftrace_ops_hash local_hash; 199 struct ftrace_ops_hash *func_hash; 200 struct ftrace_ops_hash old_hash; 201 unsigned long trampoline; 202 unsigned long trampoline_size; 203 #endif 204 }; 205 206 /* 207 * Type of the current tracing. 208 */ 209 enum ftrace_tracing_type_t { 210 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 211 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 212 }; 213 214 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 215 extern enum ftrace_tracing_type_t ftrace_tracing_type; 216 217 /* 218 * The ftrace_ops must be a static and should also 219 * be read_mostly. These functions do modify read_mostly variables 220 * so use them sparely. Never free an ftrace_op or modify the 221 * next pointer after it has been registered. Even after unregistering 222 * it, the next pointer may still be used internally. 223 */ 224 int register_ftrace_function(struct ftrace_ops *ops); 225 int unregister_ftrace_function(struct ftrace_ops *ops); 226 227 extern void ftrace_stub(unsigned long a0, unsigned long a1, 228 struct ftrace_ops *op, struct pt_regs *regs); 229 230 #else /* !CONFIG_FUNCTION_TRACER */ 231 /* 232 * (un)register_ftrace_function must be a macro since the ops parameter 233 * must not be evaluated. 234 */ 235 #define register_ftrace_function(ops) ({ 0; }) 236 #define unregister_ftrace_function(ops) ({ 0; }) 237 static inline void ftrace_kill(void) { } 238 static inline void ftrace_free_init_mem(void) { } 239 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 240 #endif /* CONFIG_FUNCTION_TRACER */ 241 242 #ifdef CONFIG_STACK_TRACER 243 244 extern int stack_tracer_enabled; 245 246 int stack_trace_sysctl(struct ctl_table *table, int write, 247 void __user *buffer, size_t *lenp, 248 loff_t *ppos); 249 250 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 251 DECLARE_PER_CPU(int, disable_stack_tracer); 252 253 /** 254 * stack_tracer_disable - temporarily disable the stack tracer 255 * 256 * There's a few locations (namely in RCU) where stack tracing 257 * cannot be executed. This function is used to disable stack 258 * tracing during those critical sections. 259 * 260 * This function must be called with preemption or interrupts 261 * disabled and stack_tracer_enable() must be called shortly after 262 * while preemption or interrupts are still disabled. 263 */ 264 static inline void stack_tracer_disable(void) 265 { 266 /* Preemption or interupts must be disabled */ 267 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 268 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 269 this_cpu_inc(disable_stack_tracer); 270 } 271 272 /** 273 * stack_tracer_enable - re-enable the stack tracer 274 * 275 * After stack_tracer_disable() is called, stack_tracer_enable() 276 * must be called shortly afterward. 277 */ 278 static inline void stack_tracer_enable(void) 279 { 280 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 281 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 282 this_cpu_dec(disable_stack_tracer); 283 } 284 #else 285 static inline void stack_tracer_disable(void) { } 286 static inline void stack_tracer_enable(void) { } 287 #endif 288 289 #ifdef CONFIG_DYNAMIC_FTRACE 290 291 int ftrace_arch_code_modify_prepare(void); 292 int ftrace_arch_code_modify_post_process(void); 293 294 struct dyn_ftrace; 295 296 enum ftrace_bug_type { 297 FTRACE_BUG_UNKNOWN, 298 FTRACE_BUG_INIT, 299 FTRACE_BUG_NOP, 300 FTRACE_BUG_CALL, 301 FTRACE_BUG_UPDATE, 302 }; 303 extern enum ftrace_bug_type ftrace_bug_type; 304 305 /* 306 * Archs can set this to point to a variable that holds the value that was 307 * expected at the call site before calling ftrace_bug(). 308 */ 309 extern const void *ftrace_expected; 310 311 void ftrace_bug(int err, struct dyn_ftrace *rec); 312 313 struct seq_file; 314 315 extern int ftrace_text_reserved(const void *start, const void *end); 316 317 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); 318 319 bool is_ftrace_trampoline(unsigned long addr); 320 321 /* 322 * The dyn_ftrace record's flags field is split into two parts. 323 * the first part which is '0-FTRACE_REF_MAX' is a counter of 324 * the number of callbacks that have registered the function that 325 * the dyn_ftrace descriptor represents. 326 * 327 * The second part is a mask: 328 * ENABLED - the function is being traced 329 * REGS - the record wants the function to save regs 330 * REGS_EN - the function is set up to save regs. 331 * IPMODIFY - the record allows for the IP address to be changed. 332 * DISABLED - the record is not ready to be touched yet 333 * 334 * When a new ftrace_ops is registered and wants a function to save 335 * pt_regs, the rec->flag REGS is set. When the function has been 336 * set up to save regs, the REG_EN flag is set. Once a function 337 * starts saving regs it will do so until all ftrace_ops are removed 338 * from tracing that function. 339 */ 340 enum { 341 FTRACE_FL_ENABLED = (1UL << 31), 342 FTRACE_FL_REGS = (1UL << 30), 343 FTRACE_FL_REGS_EN = (1UL << 29), 344 FTRACE_FL_TRAMP = (1UL << 28), 345 FTRACE_FL_TRAMP_EN = (1UL << 27), 346 FTRACE_FL_IPMODIFY = (1UL << 26), 347 FTRACE_FL_DISABLED = (1UL << 25), 348 }; 349 350 #define FTRACE_REF_MAX_SHIFT 25 351 #define FTRACE_FL_BITS 7 352 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 353 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 354 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 355 356 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 357 358 struct dyn_ftrace { 359 unsigned long ip; /* address of mcount call-site */ 360 unsigned long flags; 361 struct dyn_arch_ftrace arch; 362 }; 363 364 int ftrace_force_update(void); 365 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 366 int remove, int reset); 367 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 368 int len, int reset); 369 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 370 int len, int reset); 371 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 372 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 373 void ftrace_free_filter(struct ftrace_ops *ops); 374 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 375 376 enum { 377 FTRACE_UPDATE_CALLS = (1 << 0), 378 FTRACE_DISABLE_CALLS = (1 << 1), 379 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 380 FTRACE_START_FUNC_RET = (1 << 3), 381 FTRACE_STOP_FUNC_RET = (1 << 4), 382 FTRACE_MAY_SLEEP = (1 << 5), 383 }; 384 385 /* 386 * The FTRACE_UPDATE_* enum is used to pass information back 387 * from the ftrace_update_record() and ftrace_test_record() 388 * functions. These are called by the code update routines 389 * to find out what is to be done for a given function. 390 * 391 * IGNORE - The function is already what we want it to be 392 * MAKE_CALL - Start tracing the function 393 * MODIFY_CALL - Stop saving regs for the function 394 * MAKE_NOP - Stop tracing the function 395 */ 396 enum { 397 FTRACE_UPDATE_IGNORE, 398 FTRACE_UPDATE_MAKE_CALL, 399 FTRACE_UPDATE_MODIFY_CALL, 400 FTRACE_UPDATE_MAKE_NOP, 401 }; 402 403 enum { 404 FTRACE_ITER_FILTER = (1 << 0), 405 FTRACE_ITER_NOTRACE = (1 << 1), 406 FTRACE_ITER_PRINTALL = (1 << 2), 407 FTRACE_ITER_DO_PROBES = (1 << 3), 408 FTRACE_ITER_PROBE = (1 << 4), 409 FTRACE_ITER_MOD = (1 << 5), 410 FTRACE_ITER_ENABLED = (1 << 6), 411 }; 412 413 void arch_ftrace_update_code(int command); 414 void arch_ftrace_update_trampoline(struct ftrace_ops *ops); 415 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec); 416 void arch_ftrace_trampoline_free(struct ftrace_ops *ops); 417 418 struct ftrace_rec_iter; 419 420 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 421 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 422 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 423 424 #define for_ftrace_rec_iter(iter) \ 425 for (iter = ftrace_rec_iter_start(); \ 426 iter; \ 427 iter = ftrace_rec_iter_next(iter)) 428 429 430 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 431 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 432 void ftrace_run_stop_machine(int command); 433 unsigned long ftrace_location(unsigned long ip); 434 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 435 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 436 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 437 438 extern ftrace_func_t ftrace_trace_function; 439 440 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 441 struct inode *inode, struct file *file); 442 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 443 size_t cnt, loff_t *ppos); 444 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 445 size_t cnt, loff_t *ppos); 446 int ftrace_regex_release(struct inode *inode, struct file *file); 447 448 void __init 449 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 450 451 /* defined in arch */ 452 extern int ftrace_ip_converted(unsigned long ip); 453 extern int ftrace_dyn_arch_init(void); 454 extern void ftrace_replace_code(int enable); 455 extern int ftrace_update_ftrace_func(ftrace_func_t func); 456 extern void ftrace_caller(void); 457 extern void ftrace_regs_caller(void); 458 extern void ftrace_call(void); 459 extern void ftrace_regs_call(void); 460 extern void mcount_call(void); 461 462 void ftrace_modify_all_code(int command); 463 464 #ifndef FTRACE_ADDR 465 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 466 #endif 467 468 #ifndef FTRACE_GRAPH_ADDR 469 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 470 #endif 471 472 #ifndef FTRACE_REGS_ADDR 473 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 474 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 475 #else 476 # define FTRACE_REGS_ADDR FTRACE_ADDR 477 #endif 478 #endif 479 480 /* 481 * If an arch would like functions that are only traced 482 * by the function graph tracer to jump directly to its own 483 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 484 * to be that address to jump to. 485 */ 486 #ifndef FTRACE_GRAPH_TRAMP_ADDR 487 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 488 #endif 489 490 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 491 extern void ftrace_graph_caller(void); 492 extern int ftrace_enable_ftrace_graph_caller(void); 493 extern int ftrace_disable_ftrace_graph_caller(void); 494 #else 495 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 496 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 497 #endif 498 499 /** 500 * ftrace_make_nop - convert code into nop 501 * @mod: module structure if called by module load initialization 502 * @rec: the mcount call site record 503 * @addr: the address that the call site should be calling 504 * 505 * This is a very sensitive operation and great care needs 506 * to be taken by the arch. The operation should carefully 507 * read the location, check to see if what is read is indeed 508 * what we expect it to be, and then on success of the compare, 509 * it should write to the location. 510 * 511 * The code segment at @rec->ip should be a caller to @addr 512 * 513 * Return must be: 514 * 0 on success 515 * -EFAULT on error reading the location 516 * -EINVAL on a failed compare of the contents 517 * -EPERM on error writing to the location 518 * Any other value will be considered a failure. 519 */ 520 extern int ftrace_make_nop(struct module *mod, 521 struct dyn_ftrace *rec, unsigned long addr); 522 523 /** 524 * ftrace_make_call - convert a nop call site into a call to addr 525 * @rec: the mcount call site record 526 * @addr: the address that the call site should call 527 * 528 * This is a very sensitive operation and great care needs 529 * to be taken by the arch. The operation should carefully 530 * read the location, check to see if what is read is indeed 531 * what we expect it to be, and then on success of the compare, 532 * it should write to the location. 533 * 534 * The code segment at @rec->ip should be a nop 535 * 536 * Return must be: 537 * 0 on success 538 * -EFAULT on error reading the location 539 * -EINVAL on a failed compare of the contents 540 * -EPERM on error writing to the location 541 * Any other value will be considered a failure. 542 */ 543 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 544 545 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 546 /** 547 * ftrace_modify_call - convert from one addr to another (no nop) 548 * @rec: the mcount call site record 549 * @old_addr: the address expected to be currently called to 550 * @addr: the address to change to 551 * 552 * This is a very sensitive operation and great care needs 553 * to be taken by the arch. The operation should carefully 554 * read the location, check to see if what is read is indeed 555 * what we expect it to be, and then on success of the compare, 556 * it should write to the location. 557 * 558 * The code segment at @rec->ip should be a caller to @old_addr 559 * 560 * Return must be: 561 * 0 on success 562 * -EFAULT on error reading the location 563 * -EINVAL on a failed compare of the contents 564 * -EPERM on error writing to the location 565 * Any other value will be considered a failure. 566 */ 567 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 568 unsigned long addr); 569 #else 570 /* Should never be called */ 571 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 572 unsigned long addr) 573 { 574 return -EINVAL; 575 } 576 #endif 577 578 /* May be defined in arch */ 579 extern int ftrace_arch_read_dyn_info(char *buf, int size); 580 581 extern int skip_trace(unsigned long ip); 582 extern void ftrace_module_init(struct module *mod); 583 extern void ftrace_module_enable(struct module *mod); 584 extern void ftrace_release_mod(struct module *mod); 585 586 extern void ftrace_disable_daemon(void); 587 extern void ftrace_enable_daemon(void); 588 #else /* CONFIG_DYNAMIC_FTRACE */ 589 static inline int skip_trace(unsigned long ip) { return 0; } 590 static inline int ftrace_force_update(void) { return 0; } 591 static inline void ftrace_disable_daemon(void) { } 592 static inline void ftrace_enable_daemon(void) { } 593 static inline void ftrace_module_init(struct module *mod) { } 594 static inline void ftrace_module_enable(struct module *mod) { } 595 static inline void ftrace_release_mod(struct module *mod) { } 596 static inline int ftrace_text_reserved(const void *start, const void *end) 597 { 598 return 0; 599 } 600 static inline unsigned long ftrace_location(unsigned long ip) 601 { 602 return 0; 603 } 604 605 /* 606 * Again users of functions that have ftrace_ops may not 607 * have them defined when ftrace is not enabled, but these 608 * functions may still be called. Use a macro instead of inline. 609 */ 610 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 611 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 612 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 613 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 614 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 615 #define ftrace_free_filter(ops) do { } while (0) 616 #define ftrace_ops_set_global_filter(ops) do { } while (0) 617 618 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 619 size_t cnt, loff_t *ppos) { return -ENODEV; } 620 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 621 size_t cnt, loff_t *ppos) { return -ENODEV; } 622 static inline int 623 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 624 625 static inline bool is_ftrace_trampoline(unsigned long addr) 626 { 627 return false; 628 } 629 #endif /* CONFIG_DYNAMIC_FTRACE */ 630 631 /* totally disable ftrace - can not re-enable after this */ 632 void ftrace_kill(void); 633 634 static inline void tracer_disable(void) 635 { 636 #ifdef CONFIG_FUNCTION_TRACER 637 ftrace_enabled = 0; 638 #endif 639 } 640 641 /* 642 * Ftrace disable/restore without lock. Some synchronization mechanism 643 * must be used to prevent ftrace_enabled to be changed between 644 * disable/restore. 645 */ 646 static inline int __ftrace_enabled_save(void) 647 { 648 #ifdef CONFIG_FUNCTION_TRACER 649 int saved_ftrace_enabled = ftrace_enabled; 650 ftrace_enabled = 0; 651 return saved_ftrace_enabled; 652 #else 653 return 0; 654 #endif 655 } 656 657 static inline void __ftrace_enabled_restore(int enabled) 658 { 659 #ifdef CONFIG_FUNCTION_TRACER 660 ftrace_enabled = enabled; 661 #endif 662 } 663 664 /* All archs should have this, but we define it for consistency */ 665 #ifndef ftrace_return_address0 666 # define ftrace_return_address0 __builtin_return_address(0) 667 #endif 668 669 /* Archs may use other ways for ADDR1 and beyond */ 670 #ifndef ftrace_return_address 671 # ifdef CONFIG_FRAME_POINTER 672 # define ftrace_return_address(n) __builtin_return_address(n) 673 # else 674 # define ftrace_return_address(n) 0UL 675 # endif 676 #endif 677 678 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 679 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 680 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 681 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 682 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 683 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 684 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 685 686 static inline unsigned long get_lock_parent_ip(void) 687 { 688 unsigned long addr = CALLER_ADDR0; 689 690 if (!in_lock_functions(addr)) 691 return addr; 692 addr = CALLER_ADDR1; 693 if (!in_lock_functions(addr)) 694 return addr; 695 return CALLER_ADDR2; 696 } 697 698 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE 699 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 700 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 701 #else 702 /* 703 * Use defines instead of static inlines because some arches will make code out 704 * of the CALLER_ADDR, when we really want these to be a real nop. 705 */ 706 # define trace_preempt_on(a0, a1) do { } while (0) 707 # define trace_preempt_off(a0, a1) do { } while (0) 708 #endif 709 710 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 711 extern void ftrace_init(void); 712 #else 713 static inline void ftrace_init(void) { } 714 #endif 715 716 /* 717 * Structure that defines an entry function trace. 718 * It's already packed but the attribute "packed" is needed 719 * to remove extra padding at the end. 720 */ 721 struct ftrace_graph_ent { 722 unsigned long func; /* Current function */ 723 int depth; 724 } __packed; 725 726 /* 727 * Structure that defines a return function trace. 728 * It's already packed but the attribute "packed" is needed 729 * to remove extra padding at the end. 730 */ 731 struct ftrace_graph_ret { 732 unsigned long func; /* Current function */ 733 /* Number of functions that overran the depth limit for current task */ 734 unsigned long overrun; 735 unsigned long long calltime; 736 unsigned long long rettime; 737 int depth; 738 } __packed; 739 740 /* Type of the callback handlers for tracing function graph*/ 741 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 742 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 743 744 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); 745 746 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 747 748 struct fgraph_ops { 749 trace_func_graph_ent_t entryfunc; 750 trace_func_graph_ret_t retfunc; 751 }; 752 753 /* 754 * Stack of return addresses for functions 755 * of a thread. 756 * Used in struct thread_info 757 */ 758 struct ftrace_ret_stack { 759 unsigned long ret; 760 unsigned long func; 761 unsigned long long calltime; 762 #ifdef CONFIG_FUNCTION_PROFILER 763 unsigned long long subtime; 764 #endif 765 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 766 unsigned long fp; 767 #endif 768 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 769 unsigned long *retp; 770 #endif 771 }; 772 773 /* 774 * Primary handler of a function return. 775 * It relays on ftrace_return_to_handler. 776 * Defined in entry_32/64.S 777 */ 778 extern void return_to_handler(void); 779 780 extern int 781 function_graph_enter(unsigned long ret, unsigned long func, 782 unsigned long frame_pointer, unsigned long *retp); 783 784 struct ftrace_ret_stack * 785 ftrace_graph_get_ret_stack(struct task_struct *task, int idx); 786 787 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 788 unsigned long ret, unsigned long *retp); 789 790 /* 791 * Sometimes we don't want to trace a function with the function 792 * graph tracer but we want them to keep traced by the usual function 793 * tracer if the function graph tracer is not configured. 794 */ 795 #define __notrace_funcgraph notrace 796 797 #define FTRACE_RETFUNC_DEPTH 50 798 #define FTRACE_RETSTACK_ALLOC_SIZE 32 799 800 extern int register_ftrace_graph(struct fgraph_ops *ops); 801 extern void unregister_ftrace_graph(struct fgraph_ops *ops); 802 803 extern bool ftrace_graph_is_dead(void); 804 extern void ftrace_graph_stop(void); 805 806 /* The current handlers in use */ 807 extern trace_func_graph_ret_t ftrace_graph_return; 808 extern trace_func_graph_ent_t ftrace_graph_entry; 809 810 extern void ftrace_graph_init_task(struct task_struct *t); 811 extern void ftrace_graph_exit_task(struct task_struct *t); 812 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 813 814 static inline void pause_graph_tracing(void) 815 { 816 atomic_inc(¤t->tracing_graph_pause); 817 } 818 819 static inline void unpause_graph_tracing(void) 820 { 821 atomic_dec(¤t->tracing_graph_pause); 822 } 823 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 824 825 #define __notrace_funcgraph 826 827 static inline void ftrace_graph_init_task(struct task_struct *t) { } 828 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 829 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 830 831 /* Define as macros as fgraph_ops may not be defined */ 832 #define register_ftrace_graph(ops) ({ -1; }) 833 #define unregister_ftrace_graph(ops) do { } while (0) 834 835 static inline unsigned long 836 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 837 unsigned long *retp) 838 { 839 return ret; 840 } 841 842 static inline void pause_graph_tracing(void) { } 843 static inline void unpause_graph_tracing(void) { } 844 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 845 846 #ifdef CONFIG_TRACING 847 848 /* flags for current->trace */ 849 enum { 850 TSK_TRACE_FL_TRACE_BIT = 0, 851 TSK_TRACE_FL_GRAPH_BIT = 1, 852 }; 853 enum { 854 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 855 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 856 }; 857 858 static inline void set_tsk_trace_trace(struct task_struct *tsk) 859 { 860 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 861 } 862 863 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 864 { 865 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 866 } 867 868 static inline int test_tsk_trace_trace(struct task_struct *tsk) 869 { 870 return tsk->trace & TSK_TRACE_FL_TRACE; 871 } 872 873 static inline void set_tsk_trace_graph(struct task_struct *tsk) 874 { 875 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 876 } 877 878 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 879 { 880 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 881 } 882 883 static inline int test_tsk_trace_graph(struct task_struct *tsk) 884 { 885 return tsk->trace & TSK_TRACE_FL_GRAPH; 886 } 887 888 enum ftrace_dump_mode; 889 890 extern enum ftrace_dump_mode ftrace_dump_on_oops; 891 extern int tracepoint_printk; 892 893 extern void disable_trace_on_warning(void); 894 extern int __disable_trace_on_warning; 895 896 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 897 void __user *buffer, size_t *lenp, 898 loff_t *ppos); 899 900 #else /* CONFIG_TRACING */ 901 static inline void disable_trace_on_warning(void) { } 902 #endif /* CONFIG_TRACING */ 903 904 #ifdef CONFIG_FTRACE_SYSCALLS 905 906 unsigned long arch_syscall_addr(int nr); 907 908 #endif /* CONFIG_FTRACE_SYSCALLS */ 909 910 #endif /* _LINUX_FTRACE_H */ 911