1/* 2 * Ftrace header. For implementation details beyond the random comments 3 * scattered below, see: Documentation/trace/ftrace-design.txt 4 */ 5 6#ifndef _LINUX_FTRACE_H 7#define _LINUX_FTRACE_H 8 9#include <linux/trace_clock.h> 10#include <linux/kallsyms.h> 11#include <linux/linkage.h> 12#include <linux/bitops.h> 13#include <linux/ptrace.h> 14#include <linux/ktime.h> 15#include <linux/sched.h> 16#include <linux/types.h> 17#include <linux/init.h> 18#include <linux/fs.h> 19 20#include <asm/ftrace.h> 21 22/* 23 * If the arch supports passing the variable contents of 24 * function_trace_op as the third parameter back from the 25 * mcount call, then the arch should define this as 1. 26 */ 27#ifndef ARCH_SUPPORTS_FTRACE_OPS 28#define ARCH_SUPPORTS_FTRACE_OPS 0 29#endif 30 31/* 32 * If the arch's mcount caller does not support all of ftrace's 33 * features, then it must call an indirect function that 34 * does. Or at least does enough to prevent any unwelcomed side effects. 35 */ 36#if !ARCH_SUPPORTS_FTRACE_OPS 37# define FTRACE_FORCE_LIST_FUNC 1 38#else 39# define FTRACE_FORCE_LIST_FUNC 0 40#endif 41 42/* Main tracing buffer and events set up */ 43#ifdef CONFIG_TRACING 44void trace_init(void); 45#else 46static inline void trace_init(void) { } 47#endif 48 49struct module; 50struct ftrace_hash; 51 52#ifdef CONFIG_FUNCTION_TRACER 53 54extern int ftrace_enabled; 55extern int 56ftrace_enable_sysctl(struct ctl_table *table, int write, 57 void __user *buffer, size_t *lenp, 58 loff_t *ppos); 59 60struct ftrace_ops; 61 62typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 63 struct ftrace_ops *op, struct pt_regs *regs); 64 65ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 66 67/* 68 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 69 * set in the flags member. 70 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION_SAFE, STUB and 71 * IPMODIFY are a kind of attribute flags which can be set only before 72 * registering the ftrace_ops, and can not be modified while registered. 73 * Changing those attribute flags after regsitering ftrace_ops will 74 * cause unexpected results. 75 * 76 * ENABLED - set/unset when ftrace_ops is registered/unregistered 77 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 78 * allocated ftrace_ops which need special care 79 * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops 80 * could be controled by following calls: 81 * ftrace_function_local_enable 82 * ftrace_function_local_disable 83 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 84 * and passed to the callback. If this flag is set, but the 85 * architecture does not support passing regs 86 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 87 * ftrace_ops will fail to register, unless the next flag 88 * is set. 89 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 90 * handler can handle an arch that does not save regs 91 * (the handler tests if regs == NULL), then it can set 92 * this flag instead. It will not fail registering the ftrace_ops 93 * but, the regs field will be NULL if the arch does not support 94 * passing regs to the handler. 95 * Note, if this flag is set, the SAVE_REGS flag will automatically 96 * get set upon registering the ftrace_ops, if the arch supports it. 97 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure 98 * that the call back has its own recursion protection. If it does 99 * not set this, then the ftrace infrastructure will add recursion 100 * protection for the caller. 101 * STUB - The ftrace_ops is just a place holder. 102 * INITIALIZED - The ftrace_ops has already been initialized (first use time 103 * register_ftrace_function() is called, it will initialized the ops) 104 * DELETED - The ops are being deleted, do not let them be registered again. 105 * ADDING - The ops is in the process of being added. 106 * REMOVING - The ops is in the process of being removed. 107 * MODIFYING - The ops is in the process of changing its filter functions. 108 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 109 * The arch specific code sets this flag when it allocated a 110 * trampoline. This lets the arch know that it can update the 111 * trampoline in case the callback function changes. 112 * The ftrace_ops trampoline can be set by the ftrace users, and 113 * in such cases the arch must not modify it. Only the arch ftrace 114 * core code should set this flag. 115 * IPMODIFY - The ops can modify the IP register. This can only be set with 116 * SAVE_REGS. If another ops with this flag set is already registered 117 * for any of the functions that this ops will be registered for, then 118 * this ops will fail to register or set_filter_ip. 119 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 120 */ 121enum { 122 FTRACE_OPS_FL_ENABLED = 1 << 0, 123 FTRACE_OPS_FL_DYNAMIC = 1 << 1, 124 FTRACE_OPS_FL_CONTROL = 1 << 2, 125 FTRACE_OPS_FL_SAVE_REGS = 1 << 3, 126 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 4, 127 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 5, 128 FTRACE_OPS_FL_STUB = 1 << 6, 129 FTRACE_OPS_FL_INITIALIZED = 1 << 7, 130 FTRACE_OPS_FL_DELETED = 1 << 8, 131 FTRACE_OPS_FL_ADDING = 1 << 9, 132 FTRACE_OPS_FL_REMOVING = 1 << 10, 133 FTRACE_OPS_FL_MODIFYING = 1 << 11, 134 FTRACE_OPS_FL_ALLOC_TRAMP = 1 << 12, 135 FTRACE_OPS_FL_IPMODIFY = 1 << 13, 136 FTRACE_OPS_FL_PID = 1 << 14, 137}; 138 139#ifdef CONFIG_DYNAMIC_FTRACE 140/* The hash used to know what functions callbacks trace */ 141struct ftrace_ops_hash { 142 struct ftrace_hash *notrace_hash; 143 struct ftrace_hash *filter_hash; 144 struct mutex regex_lock; 145}; 146#endif 147 148/* 149 * Note, ftrace_ops can be referenced outside of RCU protection. 150 * (Although, for perf, the control ops prevent that). If ftrace_ops is 151 * allocated and not part of kernel core data, the unregistering of it will 152 * perform a scheduling on all CPUs to make sure that there are no more users. 153 * Depending on the load of the system that may take a bit of time. 154 * 155 * Any private data added must also take care not to be freed and if private 156 * data is added to a ftrace_ops that is in core code, the user of the 157 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 158 */ 159struct ftrace_ops { 160 ftrace_func_t func; 161 struct ftrace_ops *next; 162 unsigned long flags; 163 void *private; 164 ftrace_func_t saved_func; 165 int __percpu *disabled; 166#ifdef CONFIG_DYNAMIC_FTRACE 167 int nr_trampolines; 168 struct ftrace_ops_hash local_hash; 169 struct ftrace_ops_hash *func_hash; 170 struct ftrace_ops_hash old_hash; 171 unsigned long trampoline; 172 unsigned long trampoline_size; 173#endif 174}; 175 176/* 177 * Type of the current tracing. 178 */ 179enum ftrace_tracing_type_t { 180 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 181 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 182}; 183 184/* Current tracing type, default is FTRACE_TYPE_ENTER */ 185extern enum ftrace_tracing_type_t ftrace_tracing_type; 186 187/* 188 * The ftrace_ops must be a static and should also 189 * be read_mostly. These functions do modify read_mostly variables 190 * so use them sparely. Never free an ftrace_op or modify the 191 * next pointer after it has been registered. Even after unregistering 192 * it, the next pointer may still be used internally. 193 */ 194int register_ftrace_function(struct ftrace_ops *ops); 195int unregister_ftrace_function(struct ftrace_ops *ops); 196void clear_ftrace_function(void); 197 198/** 199 * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu 200 * 201 * This function enables tracing on current cpu by decreasing 202 * the per cpu control variable. 203 * It must be called with preemption disabled and only on ftrace_ops 204 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 205 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 206 */ 207static inline void ftrace_function_local_enable(struct ftrace_ops *ops) 208{ 209 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 210 return; 211 212 (*this_cpu_ptr(ops->disabled))--; 213} 214 215/** 216 * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu 217 * 218 * This function enables tracing on current cpu by decreasing 219 * the per cpu control variable. 220 * It must be called with preemption disabled and only on ftrace_ops 221 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 222 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 223 */ 224static inline void ftrace_function_local_disable(struct ftrace_ops *ops) 225{ 226 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 227 return; 228 229 (*this_cpu_ptr(ops->disabled))++; 230} 231 232/** 233 * ftrace_function_local_disabled - returns ftrace_ops disabled value 234 * on current cpu 235 * 236 * This function returns value of ftrace_ops::disabled on current cpu. 237 * It must be called with preemption disabled and only on ftrace_ops 238 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 239 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 240 */ 241static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) 242{ 243 WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)); 244 return *this_cpu_ptr(ops->disabled); 245} 246 247extern void ftrace_stub(unsigned long a0, unsigned long a1, 248 struct ftrace_ops *op, struct pt_regs *regs); 249 250#else /* !CONFIG_FUNCTION_TRACER */ 251/* 252 * (un)register_ftrace_function must be a macro since the ops parameter 253 * must not be evaluated. 254 */ 255#define register_ftrace_function(ops) ({ 0; }) 256#define unregister_ftrace_function(ops) ({ 0; }) 257static inline int ftrace_nr_registered_ops(void) 258{ 259 return 0; 260} 261static inline void clear_ftrace_function(void) { } 262static inline void ftrace_kill(void) { } 263#endif /* CONFIG_FUNCTION_TRACER */ 264 265#ifdef CONFIG_STACK_TRACER 266extern int stack_tracer_enabled; 267int 268stack_trace_sysctl(struct ctl_table *table, int write, 269 void __user *buffer, size_t *lenp, 270 loff_t *ppos); 271#endif 272 273struct ftrace_func_command { 274 struct list_head list; 275 char *name; 276 int (*func)(struct ftrace_hash *hash, 277 char *func, char *cmd, 278 char *params, int enable); 279}; 280 281#ifdef CONFIG_DYNAMIC_FTRACE 282 283int ftrace_arch_code_modify_prepare(void); 284int ftrace_arch_code_modify_post_process(void); 285 286struct dyn_ftrace; 287 288void ftrace_bug(int err, struct dyn_ftrace *rec); 289 290struct seq_file; 291 292struct ftrace_probe_ops { 293 void (*func)(unsigned long ip, 294 unsigned long parent_ip, 295 void **data); 296 int (*init)(struct ftrace_probe_ops *ops, 297 unsigned long ip, void **data); 298 void (*free)(struct ftrace_probe_ops *ops, 299 unsigned long ip, void **data); 300 int (*print)(struct seq_file *m, 301 unsigned long ip, 302 struct ftrace_probe_ops *ops, 303 void *data); 304}; 305 306extern int 307register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 308 void *data); 309extern void 310unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 311 void *data); 312extern void 313unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops); 314extern void unregister_ftrace_function_probe_all(char *glob); 315 316extern int ftrace_text_reserved(const void *start, const void *end); 317 318extern int ftrace_nr_registered_ops(void); 319 320bool is_ftrace_trampoline(unsigned long addr); 321 322/* 323 * The dyn_ftrace record's flags field is split into two parts. 324 * the first part which is '0-FTRACE_REF_MAX' is a counter of 325 * the number of callbacks that have registered the function that 326 * the dyn_ftrace descriptor represents. 327 * 328 * The second part is a mask: 329 * ENABLED - the function is being traced 330 * REGS - the record wants the function to save regs 331 * REGS_EN - the function is set up to save regs. 332 * IPMODIFY - the record allows for the IP address to be changed. 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 */ 340enum { 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}; 348 349#define FTRACE_REF_MAX_SHIFT 26 350#define FTRACE_FL_BITS 6 351#define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 352#define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 353#define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 354 355#define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 356 357struct dyn_ftrace { 358 unsigned long ip; /* address of mcount call-site */ 359 unsigned long flags; 360 struct dyn_arch_ftrace arch; 361}; 362 363int ftrace_force_update(void); 364int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 365 int remove, int reset); 366int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 367 int len, int reset); 368int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 369 int len, int reset); 370void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 371void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 372void ftrace_free_filter(struct ftrace_ops *ops); 373 374int register_ftrace_command(struct ftrace_func_command *cmd); 375int unregister_ftrace_command(struct ftrace_func_command *cmd); 376 377enum { 378 FTRACE_UPDATE_CALLS = (1 << 0), 379 FTRACE_DISABLE_CALLS = (1 << 1), 380 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 381 FTRACE_START_FUNC_RET = (1 << 3), 382 FTRACE_STOP_FUNC_RET = (1 << 4), 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 */ 396enum { 397 FTRACE_UPDATE_IGNORE, 398 FTRACE_UPDATE_MAKE_CALL, 399 FTRACE_UPDATE_MODIFY_CALL, 400 FTRACE_UPDATE_MAKE_NOP, 401}; 402 403enum { 404 FTRACE_ITER_FILTER = (1 << 0), 405 FTRACE_ITER_NOTRACE = (1 << 1), 406 FTRACE_ITER_PRINTALL = (1 << 2), 407 FTRACE_ITER_DO_HASH = (1 << 3), 408 FTRACE_ITER_HASH = (1 << 4), 409 FTRACE_ITER_ENABLED = (1 << 5), 410}; 411 412void arch_ftrace_update_code(int command); 413 414struct ftrace_rec_iter; 415 416struct ftrace_rec_iter *ftrace_rec_iter_start(void); 417struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 418struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 419 420#define for_ftrace_rec_iter(iter) \ 421 for (iter = ftrace_rec_iter_start(); \ 422 iter; \ 423 iter = ftrace_rec_iter_next(iter)) 424 425 426int ftrace_update_record(struct dyn_ftrace *rec, int enable); 427int ftrace_test_record(struct dyn_ftrace *rec, int enable); 428void ftrace_run_stop_machine(int command); 429unsigned long ftrace_location(unsigned long ip); 430unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 431unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 432 433extern ftrace_func_t ftrace_trace_function; 434 435int ftrace_regex_open(struct ftrace_ops *ops, int flag, 436 struct inode *inode, struct file *file); 437ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 438 size_t cnt, loff_t *ppos); 439ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 440 size_t cnt, loff_t *ppos); 441int ftrace_regex_release(struct inode *inode, struct file *file); 442 443void __init 444ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 445 446/* defined in arch */ 447extern int ftrace_ip_converted(unsigned long ip); 448extern int ftrace_dyn_arch_init(void); 449extern void ftrace_replace_code(int enable); 450extern int ftrace_update_ftrace_func(ftrace_func_t func); 451extern void ftrace_caller(void); 452extern void ftrace_regs_caller(void); 453extern void ftrace_call(void); 454extern void ftrace_regs_call(void); 455extern void mcount_call(void); 456 457void ftrace_modify_all_code(int command); 458 459#ifndef FTRACE_ADDR 460#define FTRACE_ADDR ((unsigned long)ftrace_caller) 461#endif 462 463#ifndef FTRACE_GRAPH_ADDR 464#define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 465#endif 466 467#ifndef FTRACE_REGS_ADDR 468#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 469# define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 470#else 471# define FTRACE_REGS_ADDR FTRACE_ADDR 472#endif 473#endif 474 475/* 476 * If an arch would like functions that are only traced 477 * by the function graph tracer to jump directly to its own 478 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 479 * to be that address to jump to. 480 */ 481#ifndef FTRACE_GRAPH_TRAMP_ADDR 482#define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 483#endif 484 485#ifdef CONFIG_FUNCTION_GRAPH_TRACER 486extern void ftrace_graph_caller(void); 487extern int ftrace_enable_ftrace_graph_caller(void); 488extern int ftrace_disable_ftrace_graph_caller(void); 489#else 490static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 491static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 492#endif 493 494/** 495 * ftrace_make_nop - convert code into nop 496 * @mod: module structure if called by module load initialization 497 * @rec: the mcount call site record 498 * @addr: the address that the call site should be calling 499 * 500 * This is a very sensitive operation and great care needs 501 * to be taken by the arch. The operation should carefully 502 * read the location, check to see if what is read is indeed 503 * what we expect it to be, and then on success of the compare, 504 * it should write to the location. 505 * 506 * The code segment at @rec->ip should be a caller to @addr 507 * 508 * Return must be: 509 * 0 on success 510 * -EFAULT on error reading the location 511 * -EINVAL on a failed compare of the contents 512 * -EPERM on error writing to the location 513 * Any other value will be considered a failure. 514 */ 515extern int ftrace_make_nop(struct module *mod, 516 struct dyn_ftrace *rec, unsigned long addr); 517 518/** 519 * ftrace_make_call - convert a nop call site into a call to addr 520 * @rec: the mcount call site record 521 * @addr: the address that the call site should call 522 * 523 * This is a very sensitive operation and great care needs 524 * to be taken by the arch. The operation should carefully 525 * read the location, check to see if what is read is indeed 526 * what we expect it to be, and then on success of the compare, 527 * it should write to the location. 528 * 529 * The code segment at @rec->ip should be a nop 530 * 531 * Return must be: 532 * 0 on success 533 * -EFAULT on error reading the location 534 * -EINVAL on a failed compare of the contents 535 * -EPERM on error writing to the location 536 * Any other value will be considered a failure. 537 */ 538extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 539 540#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 541/** 542 * ftrace_modify_call - convert from one addr to another (no nop) 543 * @rec: the mcount call site record 544 * @old_addr: the address expected to be currently called to 545 * @addr: the address to change to 546 * 547 * This is a very sensitive operation and great care needs 548 * to be taken by the arch. The operation should carefully 549 * read the location, check to see if what is read is indeed 550 * what we expect it to be, and then on success of the compare, 551 * it should write to the location. 552 * 553 * The code segment at @rec->ip should be a caller to @old_addr 554 * 555 * Return must be: 556 * 0 on success 557 * -EFAULT on error reading the location 558 * -EINVAL on a failed compare of the contents 559 * -EPERM on error writing to the location 560 * Any other value will be considered a failure. 561 */ 562extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 563 unsigned long addr); 564#else 565/* Should never be called */ 566static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 567 unsigned long addr) 568{ 569 return -EINVAL; 570} 571#endif 572 573/* May be defined in arch */ 574extern int ftrace_arch_read_dyn_info(char *buf, int size); 575 576extern int skip_trace(unsigned long ip); 577extern void ftrace_module_init(struct module *mod); 578 579extern void ftrace_disable_daemon(void); 580extern void ftrace_enable_daemon(void); 581#else /* CONFIG_DYNAMIC_FTRACE */ 582static inline int skip_trace(unsigned long ip) { return 0; } 583static inline int ftrace_force_update(void) { return 0; } 584static inline void ftrace_disable_daemon(void) { } 585static inline void ftrace_enable_daemon(void) { } 586static inline void ftrace_release_mod(struct module *mod) {} 587static inline void ftrace_module_init(struct module *mod) {} 588static inline __init int register_ftrace_command(struct ftrace_func_command *cmd) 589{ 590 return -EINVAL; 591} 592static inline __init int unregister_ftrace_command(char *cmd_name) 593{ 594 return -EINVAL; 595} 596static inline int ftrace_text_reserved(const void *start, const void *end) 597{ 598 return 0; 599} 600static 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 617static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 618 size_t cnt, loff_t *ppos) { return -ENODEV; } 619static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 620 size_t cnt, loff_t *ppos) { return -ENODEV; } 621static inline int 622ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 623 624static inline bool is_ftrace_trampoline(unsigned long addr) 625{ 626 return false; 627} 628#endif /* CONFIG_DYNAMIC_FTRACE */ 629 630/* totally disable ftrace - can not re-enable after this */ 631void ftrace_kill(void); 632 633static inline void tracer_disable(void) 634{ 635#ifdef CONFIG_FUNCTION_TRACER 636 ftrace_enabled = 0; 637#endif 638} 639 640/* 641 * Ftrace disable/restore without lock. Some synchronization mechanism 642 * must be used to prevent ftrace_enabled to be changed between 643 * disable/restore. 644 */ 645static inline int __ftrace_enabled_save(void) 646{ 647#ifdef CONFIG_FUNCTION_TRACER 648 int saved_ftrace_enabled = ftrace_enabled; 649 ftrace_enabled = 0; 650 return saved_ftrace_enabled; 651#else 652 return 0; 653#endif 654} 655 656static inline void __ftrace_enabled_restore(int enabled) 657{ 658#ifdef CONFIG_FUNCTION_TRACER 659 ftrace_enabled = enabled; 660#endif 661} 662 663/* All archs should have this, but we define it for consistency */ 664#ifndef ftrace_return_address0 665# define ftrace_return_address0 __builtin_return_address(0) 666#endif 667 668/* Archs may use other ways for ADDR1 and beyond */ 669#ifndef ftrace_return_address 670# ifdef CONFIG_FRAME_POINTER 671# define ftrace_return_address(n) __builtin_return_address(n) 672# else 673# define ftrace_return_address(n) 0UL 674# endif 675#endif 676 677#define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 678#define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 679#define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 680#define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 681#define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 682#define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 683#define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 684 685#ifdef CONFIG_IRQSOFF_TRACER 686 extern void time_hardirqs_on(unsigned long a0, unsigned long a1); 687 extern void time_hardirqs_off(unsigned long a0, unsigned long a1); 688#else 689 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } 690 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } 691#endif 692 693#ifdef CONFIG_PREEMPT_TRACER 694 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 695 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 696#else 697/* 698 * Use defines instead of static inlines because some arches will make code out 699 * of the CALLER_ADDR, when we really want these to be a real nop. 700 */ 701# define trace_preempt_on(a0, a1) do { } while (0) 702# define trace_preempt_off(a0, a1) do { } while (0) 703#endif 704 705#ifdef CONFIG_FTRACE_MCOUNT_RECORD 706extern void ftrace_init(void); 707#else 708static inline void ftrace_init(void) { } 709#endif 710 711/* 712 * Structure that defines an entry function trace. 713 */ 714struct ftrace_graph_ent { 715 unsigned long func; /* Current function */ 716 int depth; 717}; 718 719/* 720 * Structure that defines a return function trace. 721 */ 722struct ftrace_graph_ret { 723 unsigned long func; /* Current function */ 724 unsigned long long calltime; 725 unsigned long long rettime; 726 /* Number of functions that overran the depth limit for current task */ 727 unsigned long overrun; 728 int depth; 729}; 730 731/* Type of the callback handlers for tracing function graph*/ 732typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 733typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 734 735#ifdef CONFIG_FUNCTION_GRAPH_TRACER 736 737/* for init task */ 738#define INIT_FTRACE_GRAPH .ret_stack = NULL, 739 740/* 741 * Stack of return addresses for functions 742 * of a thread. 743 * Used in struct thread_info 744 */ 745struct ftrace_ret_stack { 746 unsigned long ret; 747 unsigned long func; 748 unsigned long long calltime; 749 unsigned long long subtime; 750 unsigned long fp; 751}; 752 753/* 754 * Primary handler of a function return. 755 * It relays on ftrace_return_to_handler. 756 * Defined in entry_32/64.S 757 */ 758extern void return_to_handler(void); 759 760extern int 761ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 762 unsigned long frame_pointer); 763 764/* 765 * Sometimes we don't want to trace a function with the function 766 * graph tracer but we want them to keep traced by the usual function 767 * tracer if the function graph tracer is not configured. 768 */ 769#define __notrace_funcgraph notrace 770 771/* 772 * We want to which function is an entrypoint of a hardirq. 773 * That will help us to put a signal on output. 774 */ 775#define __irq_entry __attribute__((__section__(".irqentry.text"))) 776 777/* Limits of hardirq entrypoints */ 778extern char __irqentry_text_start[]; 779extern char __irqentry_text_end[]; 780 781#define FTRACE_NOTRACE_DEPTH 65536 782#define FTRACE_RETFUNC_DEPTH 50 783#define FTRACE_RETSTACK_ALLOC_SIZE 32 784extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 785 trace_func_graph_ent_t entryfunc); 786 787extern bool ftrace_graph_is_dead(void); 788extern void ftrace_graph_stop(void); 789 790/* The current handlers in use */ 791extern trace_func_graph_ret_t ftrace_graph_return; 792extern trace_func_graph_ent_t ftrace_graph_entry; 793 794extern void unregister_ftrace_graph(void); 795 796extern void ftrace_graph_init_task(struct task_struct *t); 797extern void ftrace_graph_exit_task(struct task_struct *t); 798extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 799 800static inline int task_curr_ret_stack(struct task_struct *t) 801{ 802 return t->curr_ret_stack; 803} 804 805static inline void pause_graph_tracing(void) 806{ 807 atomic_inc(¤t->tracing_graph_pause); 808} 809 810static inline void unpause_graph_tracing(void) 811{ 812 atomic_dec(¤t->tracing_graph_pause); 813} 814#else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 815 816#define __notrace_funcgraph 817#define __irq_entry 818#define INIT_FTRACE_GRAPH 819 820static inline void ftrace_graph_init_task(struct task_struct *t) { } 821static inline void ftrace_graph_exit_task(struct task_struct *t) { } 822static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 823 824static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 825 trace_func_graph_ent_t entryfunc) 826{ 827 return -1; 828} 829static inline void unregister_ftrace_graph(void) { } 830 831static inline int task_curr_ret_stack(struct task_struct *tsk) 832{ 833 return -1; 834} 835 836static inline void pause_graph_tracing(void) { } 837static inline void unpause_graph_tracing(void) { } 838#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 839 840#ifdef CONFIG_TRACING 841 842/* flags for current->trace */ 843enum { 844 TSK_TRACE_FL_TRACE_BIT = 0, 845 TSK_TRACE_FL_GRAPH_BIT = 1, 846}; 847enum { 848 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 849 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 850}; 851 852static inline void set_tsk_trace_trace(struct task_struct *tsk) 853{ 854 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 855} 856 857static inline void clear_tsk_trace_trace(struct task_struct *tsk) 858{ 859 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 860} 861 862static inline int test_tsk_trace_trace(struct task_struct *tsk) 863{ 864 return tsk->trace & TSK_TRACE_FL_TRACE; 865} 866 867static inline void set_tsk_trace_graph(struct task_struct *tsk) 868{ 869 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 870} 871 872static inline void clear_tsk_trace_graph(struct task_struct *tsk) 873{ 874 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 875} 876 877static inline int test_tsk_trace_graph(struct task_struct *tsk) 878{ 879 return tsk->trace & TSK_TRACE_FL_GRAPH; 880} 881 882enum ftrace_dump_mode; 883 884extern enum ftrace_dump_mode ftrace_dump_on_oops; 885extern int tracepoint_printk; 886 887extern void disable_trace_on_warning(void); 888extern int __disable_trace_on_warning; 889 890#ifdef CONFIG_PREEMPT 891#define INIT_TRACE_RECURSION .trace_recursion = 0, 892#endif 893 894#else /* CONFIG_TRACING */ 895static inline void disable_trace_on_warning(void) { } 896#endif /* CONFIG_TRACING */ 897 898#ifndef INIT_TRACE_RECURSION 899#define INIT_TRACE_RECURSION 900#endif 901 902#ifdef CONFIG_FTRACE_SYSCALLS 903 904unsigned long arch_syscall_addr(int nr); 905 906#endif /* CONFIG_FTRACE_SYSCALLS */ 907 908#endif /* _LINUX_FTRACE_H */ 909