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 #define STACK_TRACE_ENTRIES 500 245 246 struct stack_trace; 247 248 extern unsigned stack_trace_index[]; 249 extern struct stack_trace stack_trace_max; 250 extern unsigned long stack_trace_max_size; 251 extern arch_spinlock_t stack_trace_max_lock; 252 253 extern int stack_tracer_enabled; 254 void stack_trace_print(void); 255 int 256 stack_trace_sysctl(struct ctl_table *table, int write, 257 void __user *buffer, size_t *lenp, 258 loff_t *ppos); 259 260 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 261 DECLARE_PER_CPU(int, disable_stack_tracer); 262 263 /** 264 * stack_tracer_disable - temporarily disable the stack tracer 265 * 266 * There's a few locations (namely in RCU) where stack tracing 267 * cannot be executed. This function is used to disable stack 268 * tracing during those critical sections. 269 * 270 * This function must be called with preemption or interrupts 271 * disabled and stack_tracer_enable() must be called shortly after 272 * while preemption or interrupts are still disabled. 273 */ 274 static inline void stack_tracer_disable(void) 275 { 276 /* Preemption or interupts must be disabled */ 277 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 278 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 279 this_cpu_inc(disable_stack_tracer); 280 } 281 282 /** 283 * stack_tracer_enable - re-enable the stack tracer 284 * 285 * After stack_tracer_disable() is called, stack_tracer_enable() 286 * must be called shortly afterward. 287 */ 288 static inline void stack_tracer_enable(void) 289 { 290 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 291 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 292 this_cpu_dec(disable_stack_tracer); 293 } 294 #else 295 static inline void stack_tracer_disable(void) { } 296 static inline void stack_tracer_enable(void) { } 297 #endif 298 299 #ifdef CONFIG_DYNAMIC_FTRACE 300 301 int ftrace_arch_code_modify_prepare(void); 302 int ftrace_arch_code_modify_post_process(void); 303 304 struct dyn_ftrace; 305 306 enum ftrace_bug_type { 307 FTRACE_BUG_UNKNOWN, 308 FTRACE_BUG_INIT, 309 FTRACE_BUG_NOP, 310 FTRACE_BUG_CALL, 311 FTRACE_BUG_UPDATE, 312 }; 313 extern enum ftrace_bug_type ftrace_bug_type; 314 315 /* 316 * Archs can set this to point to a variable that holds the value that was 317 * expected at the call site before calling ftrace_bug(). 318 */ 319 extern const void *ftrace_expected; 320 321 void ftrace_bug(int err, struct dyn_ftrace *rec); 322 323 struct seq_file; 324 325 extern int ftrace_text_reserved(const void *start, const void *end); 326 327 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); 328 329 bool is_ftrace_trampoline(unsigned long addr); 330 331 /* 332 * The dyn_ftrace record's flags field is split into two parts. 333 * the first part which is '0-FTRACE_REF_MAX' is a counter of 334 * the number of callbacks that have registered the function that 335 * the dyn_ftrace descriptor represents. 336 * 337 * The second part is a mask: 338 * ENABLED - the function is being traced 339 * REGS - the record wants the function to save regs 340 * REGS_EN - the function is set up to save regs. 341 * IPMODIFY - the record allows for the IP address to be changed. 342 * DISABLED - the record is not ready to be touched yet 343 * 344 * When a new ftrace_ops is registered and wants a function to save 345 * pt_regs, the rec->flag REGS is set. When the function has been 346 * set up to save regs, the REG_EN flag is set. Once a function 347 * starts saving regs it will do so until all ftrace_ops are removed 348 * from tracing that function. 349 */ 350 enum { 351 FTRACE_FL_ENABLED = (1UL << 31), 352 FTRACE_FL_REGS = (1UL << 30), 353 FTRACE_FL_REGS_EN = (1UL << 29), 354 FTRACE_FL_TRAMP = (1UL << 28), 355 FTRACE_FL_TRAMP_EN = (1UL << 27), 356 FTRACE_FL_IPMODIFY = (1UL << 26), 357 FTRACE_FL_DISABLED = (1UL << 25), 358 }; 359 360 #define FTRACE_REF_MAX_SHIFT 25 361 #define FTRACE_FL_BITS 7 362 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 363 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 364 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 365 366 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 367 368 struct dyn_ftrace { 369 unsigned long ip; /* address of mcount call-site */ 370 unsigned long flags; 371 struct dyn_arch_ftrace arch; 372 }; 373 374 int ftrace_force_update(void); 375 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 376 int remove, int reset); 377 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 378 int len, int reset); 379 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 380 int len, int reset); 381 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 382 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 383 void ftrace_free_filter(struct ftrace_ops *ops); 384 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 385 386 enum { 387 FTRACE_UPDATE_CALLS = (1 << 0), 388 FTRACE_DISABLE_CALLS = (1 << 1), 389 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 390 FTRACE_START_FUNC_RET = (1 << 3), 391 FTRACE_STOP_FUNC_RET = (1 << 4), 392 FTRACE_MAY_SLEEP = (1 << 5), 393 }; 394 395 /* 396 * The FTRACE_UPDATE_* enum is used to pass information back 397 * from the ftrace_update_record() and ftrace_test_record() 398 * functions. These are called by the code update routines 399 * to find out what is to be done for a given function. 400 * 401 * IGNORE - The function is already what we want it to be 402 * MAKE_CALL - Start tracing the function 403 * MODIFY_CALL - Stop saving regs for the function 404 * MAKE_NOP - Stop tracing the function 405 */ 406 enum { 407 FTRACE_UPDATE_IGNORE, 408 FTRACE_UPDATE_MAKE_CALL, 409 FTRACE_UPDATE_MODIFY_CALL, 410 FTRACE_UPDATE_MAKE_NOP, 411 }; 412 413 enum { 414 FTRACE_ITER_FILTER = (1 << 0), 415 FTRACE_ITER_NOTRACE = (1 << 1), 416 FTRACE_ITER_PRINTALL = (1 << 2), 417 FTRACE_ITER_DO_PROBES = (1 << 3), 418 FTRACE_ITER_PROBE = (1 << 4), 419 FTRACE_ITER_MOD = (1 << 5), 420 FTRACE_ITER_ENABLED = (1 << 6), 421 }; 422 423 void arch_ftrace_update_code(int command); 424 void arch_ftrace_update_trampoline(struct ftrace_ops *ops); 425 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec); 426 void arch_ftrace_trampoline_free(struct ftrace_ops *ops); 427 428 struct ftrace_rec_iter; 429 430 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 431 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 432 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 433 434 #define for_ftrace_rec_iter(iter) \ 435 for (iter = ftrace_rec_iter_start(); \ 436 iter; \ 437 iter = ftrace_rec_iter_next(iter)) 438 439 440 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 441 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 442 void ftrace_run_stop_machine(int command); 443 unsigned long ftrace_location(unsigned long ip); 444 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 445 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 446 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 447 448 extern ftrace_func_t ftrace_trace_function; 449 450 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 451 struct inode *inode, struct file *file); 452 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 453 size_t cnt, loff_t *ppos); 454 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 455 size_t cnt, loff_t *ppos); 456 int ftrace_regex_release(struct inode *inode, struct file *file); 457 458 void __init 459 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 460 461 /* defined in arch */ 462 extern int ftrace_ip_converted(unsigned long ip); 463 extern int ftrace_dyn_arch_init(void); 464 extern void ftrace_replace_code(int enable); 465 extern int ftrace_update_ftrace_func(ftrace_func_t func); 466 extern void ftrace_caller(void); 467 extern void ftrace_regs_caller(void); 468 extern void ftrace_call(void); 469 extern void ftrace_regs_call(void); 470 extern void mcount_call(void); 471 472 void ftrace_modify_all_code(int command); 473 474 #ifndef FTRACE_ADDR 475 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 476 #endif 477 478 #ifndef FTRACE_GRAPH_ADDR 479 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 480 #endif 481 482 #ifndef FTRACE_REGS_ADDR 483 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 484 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 485 #else 486 # define FTRACE_REGS_ADDR FTRACE_ADDR 487 #endif 488 #endif 489 490 /* 491 * If an arch would like functions that are only traced 492 * by the function graph tracer to jump directly to its own 493 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 494 * to be that address to jump to. 495 */ 496 #ifndef FTRACE_GRAPH_TRAMP_ADDR 497 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 498 #endif 499 500 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 501 extern void ftrace_graph_caller(void); 502 extern int ftrace_enable_ftrace_graph_caller(void); 503 extern int ftrace_disable_ftrace_graph_caller(void); 504 #else 505 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 506 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 507 #endif 508 509 /** 510 * ftrace_make_nop - convert code into nop 511 * @mod: module structure if called by module load initialization 512 * @rec: the mcount call site record 513 * @addr: the address that the call site should be calling 514 * 515 * This is a very sensitive operation and great care needs 516 * to be taken by the arch. The operation should carefully 517 * read the location, check to see if what is read is indeed 518 * what we expect it to be, and then on success of the compare, 519 * it should write to the location. 520 * 521 * The code segment at @rec->ip should be a caller to @addr 522 * 523 * Return must be: 524 * 0 on success 525 * -EFAULT on error reading the location 526 * -EINVAL on a failed compare of the contents 527 * -EPERM on error writing to the location 528 * Any other value will be considered a failure. 529 */ 530 extern int ftrace_make_nop(struct module *mod, 531 struct dyn_ftrace *rec, unsigned long addr); 532 533 /** 534 * ftrace_make_call - convert a nop call site into a call to addr 535 * @rec: the mcount call site record 536 * @addr: the address that the call site should call 537 * 538 * This is a very sensitive operation and great care needs 539 * to be taken by the arch. The operation should carefully 540 * read the location, check to see if what is read is indeed 541 * what we expect it to be, and then on success of the compare, 542 * it should write to the location. 543 * 544 * The code segment at @rec->ip should be a nop 545 * 546 * Return must be: 547 * 0 on success 548 * -EFAULT on error reading the location 549 * -EINVAL on a failed compare of the contents 550 * -EPERM on error writing to the location 551 * Any other value will be considered a failure. 552 */ 553 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 554 555 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 556 /** 557 * ftrace_modify_call - convert from one addr to another (no nop) 558 * @rec: the mcount call site record 559 * @old_addr: the address expected to be currently called to 560 * @addr: the address to change to 561 * 562 * This is a very sensitive operation and great care needs 563 * to be taken by the arch. The operation should carefully 564 * read the location, check to see if what is read is indeed 565 * what we expect it to be, and then on success of the compare, 566 * it should write to the location. 567 * 568 * The code segment at @rec->ip should be a caller to @old_addr 569 * 570 * Return must be: 571 * 0 on success 572 * -EFAULT on error reading the location 573 * -EINVAL on a failed compare of the contents 574 * -EPERM on error writing to the location 575 * Any other value will be considered a failure. 576 */ 577 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 578 unsigned long addr); 579 #else 580 /* Should never be called */ 581 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 582 unsigned long addr) 583 { 584 return -EINVAL; 585 } 586 #endif 587 588 /* May be defined in arch */ 589 extern int ftrace_arch_read_dyn_info(char *buf, int size); 590 591 extern int skip_trace(unsigned long ip); 592 extern void ftrace_module_init(struct module *mod); 593 extern void ftrace_module_enable(struct module *mod); 594 extern void ftrace_release_mod(struct module *mod); 595 596 extern void ftrace_disable_daemon(void); 597 extern void ftrace_enable_daemon(void); 598 #else /* CONFIG_DYNAMIC_FTRACE */ 599 static inline int skip_trace(unsigned long ip) { return 0; } 600 static inline int ftrace_force_update(void) { return 0; } 601 static inline void ftrace_disable_daemon(void) { } 602 static inline void ftrace_enable_daemon(void) { } 603 static inline void ftrace_module_init(struct module *mod) { } 604 static inline void ftrace_module_enable(struct module *mod) { } 605 static inline void ftrace_release_mod(struct module *mod) { } 606 static inline int ftrace_text_reserved(const void *start, const void *end) 607 { 608 return 0; 609 } 610 static inline unsigned long ftrace_location(unsigned long ip) 611 { 612 return 0; 613 } 614 615 /* 616 * Again users of functions that have ftrace_ops may not 617 * have them defined when ftrace is not enabled, but these 618 * functions may still be called. Use a macro instead of inline. 619 */ 620 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 621 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 622 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 623 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 624 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 625 #define ftrace_free_filter(ops) do { } while (0) 626 #define ftrace_ops_set_global_filter(ops) do { } while (0) 627 628 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 629 size_t cnt, loff_t *ppos) { return -ENODEV; } 630 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 631 size_t cnt, loff_t *ppos) { return -ENODEV; } 632 static inline int 633 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 634 635 static inline bool is_ftrace_trampoline(unsigned long addr) 636 { 637 return false; 638 } 639 #endif /* CONFIG_DYNAMIC_FTRACE */ 640 641 /* totally disable ftrace - can not re-enable after this */ 642 void ftrace_kill(void); 643 644 static inline void tracer_disable(void) 645 { 646 #ifdef CONFIG_FUNCTION_TRACER 647 ftrace_enabled = 0; 648 #endif 649 } 650 651 /* 652 * Ftrace disable/restore without lock. Some synchronization mechanism 653 * must be used to prevent ftrace_enabled to be changed between 654 * disable/restore. 655 */ 656 static inline int __ftrace_enabled_save(void) 657 { 658 #ifdef CONFIG_FUNCTION_TRACER 659 int saved_ftrace_enabled = ftrace_enabled; 660 ftrace_enabled = 0; 661 return saved_ftrace_enabled; 662 #else 663 return 0; 664 #endif 665 } 666 667 static inline void __ftrace_enabled_restore(int enabled) 668 { 669 #ifdef CONFIG_FUNCTION_TRACER 670 ftrace_enabled = enabled; 671 #endif 672 } 673 674 /* All archs should have this, but we define it for consistency */ 675 #ifndef ftrace_return_address0 676 # define ftrace_return_address0 __builtin_return_address(0) 677 #endif 678 679 /* Archs may use other ways for ADDR1 and beyond */ 680 #ifndef ftrace_return_address 681 # ifdef CONFIG_FRAME_POINTER 682 # define ftrace_return_address(n) __builtin_return_address(n) 683 # else 684 # define ftrace_return_address(n) 0UL 685 # endif 686 #endif 687 688 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 689 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 690 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 691 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 692 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 693 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 694 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 695 696 static inline unsigned long get_lock_parent_ip(void) 697 { 698 unsigned long addr = CALLER_ADDR0; 699 700 if (!in_lock_functions(addr)) 701 return addr; 702 addr = CALLER_ADDR1; 703 if (!in_lock_functions(addr)) 704 return addr; 705 return CALLER_ADDR2; 706 } 707 708 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE 709 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 710 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 711 #else 712 /* 713 * Use defines instead of static inlines because some arches will make code out 714 * of the CALLER_ADDR, when we really want these to be a real nop. 715 */ 716 # define trace_preempt_on(a0, a1) do { } while (0) 717 # define trace_preempt_off(a0, a1) do { } while (0) 718 #endif 719 720 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 721 extern void ftrace_init(void); 722 #else 723 static inline void ftrace_init(void) { } 724 #endif 725 726 /* 727 * Structure that defines an entry 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_ent { 732 unsigned long func; /* Current function */ 733 int depth; 734 } __packed; 735 736 /* 737 * Structure that defines a return function trace. 738 * It's already packed but the attribute "packed" is needed 739 * to remove extra padding at the end. 740 */ 741 struct ftrace_graph_ret { 742 unsigned long func; /* Current function */ 743 /* Number of functions that overran the depth limit for current task */ 744 unsigned long overrun; 745 unsigned long long calltime; 746 unsigned long long rettime; 747 int depth; 748 } __packed; 749 750 /* Type of the callback handlers for tracing function graph*/ 751 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 752 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 753 754 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 755 756 struct fgraph_ops { 757 trace_func_graph_ent_t entryfunc; 758 trace_func_graph_ret_t retfunc; 759 }; 760 761 /* 762 * Stack of return addresses for functions 763 * of a thread. 764 * Used in struct thread_info 765 */ 766 struct ftrace_ret_stack { 767 unsigned long ret; 768 unsigned long func; 769 unsigned long long calltime; 770 #ifdef CONFIG_FUNCTION_PROFILER 771 unsigned long long subtime; 772 #endif 773 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 774 unsigned long fp; 775 #endif 776 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 777 unsigned long *retp; 778 #endif 779 }; 780 781 /* 782 * Primary handler of a function return. 783 * It relays on ftrace_return_to_handler. 784 * Defined in entry_32/64.S 785 */ 786 extern void return_to_handler(void); 787 788 extern int 789 function_graph_enter(unsigned long ret, unsigned long func, 790 unsigned long frame_pointer, unsigned long *retp); 791 792 struct ftrace_ret_stack * 793 ftrace_graph_get_ret_stack(struct task_struct *task, int idx); 794 795 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 796 unsigned long ret, unsigned long *retp); 797 798 /* 799 * Sometimes we don't want to trace a function with the function 800 * graph tracer but we want them to keep traced by the usual function 801 * tracer if the function graph tracer is not configured. 802 */ 803 #define __notrace_funcgraph notrace 804 805 #define FTRACE_RETFUNC_DEPTH 50 806 #define FTRACE_RETSTACK_ALLOC_SIZE 32 807 808 extern int register_ftrace_graph(struct fgraph_ops *ops); 809 extern void unregister_ftrace_graph(struct fgraph_ops *ops); 810 811 extern bool ftrace_graph_is_dead(void); 812 extern void ftrace_graph_stop(void); 813 814 /* The current handlers in use */ 815 extern trace_func_graph_ret_t ftrace_graph_return; 816 extern trace_func_graph_ent_t ftrace_graph_entry; 817 818 extern void ftrace_graph_init_task(struct task_struct *t); 819 extern void ftrace_graph_exit_task(struct task_struct *t); 820 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 821 822 static inline void pause_graph_tracing(void) 823 { 824 atomic_inc(¤t->tracing_graph_pause); 825 } 826 827 static inline void unpause_graph_tracing(void) 828 { 829 atomic_dec(¤t->tracing_graph_pause); 830 } 831 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 832 833 #define __notrace_funcgraph 834 835 static inline void ftrace_graph_init_task(struct task_struct *t) { } 836 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 837 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 838 839 /* Define as macros as fgraph_ops may not be defined */ 840 #define register_ftrace_graph(ops) ({ -1; }) 841 #define unregister_ftrace_graph(ops) do { } while (0) 842 843 static inline unsigned long 844 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 845 unsigned long *retp) 846 { 847 return ret; 848 } 849 850 static inline void pause_graph_tracing(void) { } 851 static inline void unpause_graph_tracing(void) { } 852 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 853 854 #ifdef CONFIG_TRACING 855 856 /* flags for current->trace */ 857 enum { 858 TSK_TRACE_FL_TRACE_BIT = 0, 859 TSK_TRACE_FL_GRAPH_BIT = 1, 860 }; 861 enum { 862 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 863 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 864 }; 865 866 static inline void set_tsk_trace_trace(struct task_struct *tsk) 867 { 868 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 869 } 870 871 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 872 { 873 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 874 } 875 876 static inline int test_tsk_trace_trace(struct task_struct *tsk) 877 { 878 return tsk->trace & TSK_TRACE_FL_TRACE; 879 } 880 881 static inline void set_tsk_trace_graph(struct task_struct *tsk) 882 { 883 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 884 } 885 886 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 887 { 888 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 889 } 890 891 static inline int test_tsk_trace_graph(struct task_struct *tsk) 892 { 893 return tsk->trace & TSK_TRACE_FL_GRAPH; 894 } 895 896 enum ftrace_dump_mode; 897 898 extern enum ftrace_dump_mode ftrace_dump_on_oops; 899 extern int tracepoint_printk; 900 901 extern void disable_trace_on_warning(void); 902 extern int __disable_trace_on_warning; 903 904 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 905 void __user *buffer, size_t *lenp, 906 loff_t *ppos); 907 908 #else /* CONFIG_TRACING */ 909 static inline void disable_trace_on_warning(void) { } 910 #endif /* CONFIG_TRACING */ 911 912 #ifdef CONFIG_FTRACE_SYSCALLS 913 914 unsigned long arch_syscall_addr(int nr); 915 916 #endif /* CONFIG_FTRACE_SYSCALLS */ 917 918 #endif /* _LINUX_FTRACE_H */ 919