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 }; 393 394 /* 395 * The FTRACE_UPDATE_* enum is used to pass information back 396 * from the ftrace_update_record() and ftrace_test_record() 397 * functions. These are called by the code update routines 398 * to find out what is to be done for a given function. 399 * 400 * IGNORE - The function is already what we want it to be 401 * MAKE_CALL - Start tracing the function 402 * MODIFY_CALL - Stop saving regs for the function 403 * MAKE_NOP - Stop tracing the function 404 */ 405 enum { 406 FTRACE_UPDATE_IGNORE, 407 FTRACE_UPDATE_MAKE_CALL, 408 FTRACE_UPDATE_MODIFY_CALL, 409 FTRACE_UPDATE_MAKE_NOP, 410 }; 411 412 enum { 413 FTRACE_ITER_FILTER = (1 << 0), 414 FTRACE_ITER_NOTRACE = (1 << 1), 415 FTRACE_ITER_PRINTALL = (1 << 2), 416 FTRACE_ITER_DO_PROBES = (1 << 3), 417 FTRACE_ITER_PROBE = (1 << 4), 418 FTRACE_ITER_MOD = (1 << 5), 419 FTRACE_ITER_ENABLED = (1 << 6), 420 }; 421 422 void arch_ftrace_update_code(int command); 423 424 struct ftrace_rec_iter; 425 426 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 427 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 428 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 429 430 #define for_ftrace_rec_iter(iter) \ 431 for (iter = ftrace_rec_iter_start(); \ 432 iter; \ 433 iter = ftrace_rec_iter_next(iter)) 434 435 436 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 437 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 438 void ftrace_run_stop_machine(int command); 439 unsigned long ftrace_location(unsigned long ip); 440 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 441 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 442 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 443 444 extern ftrace_func_t ftrace_trace_function; 445 446 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 447 struct inode *inode, struct file *file); 448 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 449 size_t cnt, loff_t *ppos); 450 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 451 size_t cnt, loff_t *ppos); 452 int ftrace_regex_release(struct inode *inode, struct file *file); 453 454 void __init 455 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 456 457 /* defined in arch */ 458 extern int ftrace_ip_converted(unsigned long ip); 459 extern int ftrace_dyn_arch_init(void); 460 extern void ftrace_replace_code(int enable); 461 extern int ftrace_update_ftrace_func(ftrace_func_t func); 462 extern void ftrace_caller(void); 463 extern void ftrace_regs_caller(void); 464 extern void ftrace_call(void); 465 extern void ftrace_regs_call(void); 466 extern void mcount_call(void); 467 468 void ftrace_modify_all_code(int command); 469 470 #ifndef FTRACE_ADDR 471 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 472 #endif 473 474 #ifndef FTRACE_GRAPH_ADDR 475 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 476 #endif 477 478 #ifndef FTRACE_REGS_ADDR 479 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 480 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 481 #else 482 # define FTRACE_REGS_ADDR FTRACE_ADDR 483 #endif 484 #endif 485 486 /* 487 * If an arch would like functions that are only traced 488 * by the function graph tracer to jump directly to its own 489 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 490 * to be that address to jump to. 491 */ 492 #ifndef FTRACE_GRAPH_TRAMP_ADDR 493 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 494 #endif 495 496 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 497 extern void ftrace_graph_caller(void); 498 extern int ftrace_enable_ftrace_graph_caller(void); 499 extern int ftrace_disable_ftrace_graph_caller(void); 500 #else 501 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 502 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 503 #endif 504 505 /** 506 * ftrace_make_nop - convert code into nop 507 * @mod: module structure if called by module load initialization 508 * @rec: the mcount call site record 509 * @addr: the address that the call site should be calling 510 * 511 * This is a very sensitive operation and great care needs 512 * to be taken by the arch. The operation should carefully 513 * read the location, check to see if what is read is indeed 514 * what we expect it to be, and then on success of the compare, 515 * it should write to the location. 516 * 517 * The code segment at @rec->ip should be a caller to @addr 518 * 519 * Return must be: 520 * 0 on success 521 * -EFAULT on error reading the location 522 * -EINVAL on a failed compare of the contents 523 * -EPERM on error writing to the location 524 * Any other value will be considered a failure. 525 */ 526 extern int ftrace_make_nop(struct module *mod, 527 struct dyn_ftrace *rec, unsigned long addr); 528 529 /** 530 * ftrace_make_call - convert a nop call site into a call to addr 531 * @rec: the mcount call site record 532 * @addr: the address that the call site should call 533 * 534 * This is a very sensitive operation and great care needs 535 * to be taken by the arch. The operation should carefully 536 * read the location, check to see if what is read is indeed 537 * what we expect it to be, and then on success of the compare, 538 * it should write to the location. 539 * 540 * The code segment at @rec->ip should be a nop 541 * 542 * Return must be: 543 * 0 on success 544 * -EFAULT on error reading the location 545 * -EINVAL on a failed compare of the contents 546 * -EPERM on error writing to the location 547 * Any other value will be considered a failure. 548 */ 549 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 550 551 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 552 /** 553 * ftrace_modify_call - convert from one addr to another (no nop) 554 * @rec: the mcount call site record 555 * @old_addr: the address expected to be currently called to 556 * @addr: the address to change to 557 * 558 * This is a very sensitive operation and great care needs 559 * to be taken by the arch. The operation should carefully 560 * read the location, check to see if what is read is indeed 561 * what we expect it to be, and then on success of the compare, 562 * it should write to the location. 563 * 564 * The code segment at @rec->ip should be a caller to @old_addr 565 * 566 * Return must be: 567 * 0 on success 568 * -EFAULT on error reading the location 569 * -EINVAL on a failed compare of the contents 570 * -EPERM on error writing to the location 571 * Any other value will be considered a failure. 572 */ 573 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 574 unsigned long addr); 575 #else 576 /* Should never be called */ 577 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 578 unsigned long addr) 579 { 580 return -EINVAL; 581 } 582 #endif 583 584 /* May be defined in arch */ 585 extern int ftrace_arch_read_dyn_info(char *buf, int size); 586 587 extern int skip_trace(unsigned long ip); 588 extern void ftrace_module_init(struct module *mod); 589 extern void ftrace_module_enable(struct module *mod); 590 extern void ftrace_release_mod(struct module *mod); 591 592 extern void ftrace_disable_daemon(void); 593 extern void ftrace_enable_daemon(void); 594 #else /* CONFIG_DYNAMIC_FTRACE */ 595 static inline int skip_trace(unsigned long ip) { return 0; } 596 static inline int ftrace_force_update(void) { return 0; } 597 static inline void ftrace_disable_daemon(void) { } 598 static inline void ftrace_enable_daemon(void) { } 599 static inline void ftrace_module_init(struct module *mod) { } 600 static inline void ftrace_module_enable(struct module *mod) { } 601 static inline void ftrace_release_mod(struct module *mod) { } 602 static inline int ftrace_text_reserved(const void *start, const void *end) 603 { 604 return 0; 605 } 606 static inline unsigned long ftrace_location(unsigned long ip) 607 { 608 return 0; 609 } 610 611 /* 612 * Again users of functions that have ftrace_ops may not 613 * have them defined when ftrace is not enabled, but these 614 * functions may still be called. Use a macro instead of inline. 615 */ 616 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 617 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 618 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 619 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 620 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 621 #define ftrace_free_filter(ops) do { } while (0) 622 #define ftrace_ops_set_global_filter(ops) do { } while (0) 623 624 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 625 size_t cnt, loff_t *ppos) { return -ENODEV; } 626 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 627 size_t cnt, loff_t *ppos) { return -ENODEV; } 628 static inline int 629 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 630 631 static inline bool is_ftrace_trampoline(unsigned long addr) 632 { 633 return false; 634 } 635 #endif /* CONFIG_DYNAMIC_FTRACE */ 636 637 /* totally disable ftrace - can not re-enable after this */ 638 void ftrace_kill(void); 639 640 static inline void tracer_disable(void) 641 { 642 #ifdef CONFIG_FUNCTION_TRACER 643 ftrace_enabled = 0; 644 #endif 645 } 646 647 /* 648 * Ftrace disable/restore without lock. Some synchronization mechanism 649 * must be used to prevent ftrace_enabled to be changed between 650 * disable/restore. 651 */ 652 static inline int __ftrace_enabled_save(void) 653 { 654 #ifdef CONFIG_FUNCTION_TRACER 655 int saved_ftrace_enabled = ftrace_enabled; 656 ftrace_enabled = 0; 657 return saved_ftrace_enabled; 658 #else 659 return 0; 660 #endif 661 } 662 663 static inline void __ftrace_enabled_restore(int enabled) 664 { 665 #ifdef CONFIG_FUNCTION_TRACER 666 ftrace_enabled = enabled; 667 #endif 668 } 669 670 /* All archs should have this, but we define it for consistency */ 671 #ifndef ftrace_return_address0 672 # define ftrace_return_address0 __builtin_return_address(0) 673 #endif 674 675 /* Archs may use other ways for ADDR1 and beyond */ 676 #ifndef ftrace_return_address 677 # ifdef CONFIG_FRAME_POINTER 678 # define ftrace_return_address(n) __builtin_return_address(n) 679 # else 680 # define ftrace_return_address(n) 0UL 681 # endif 682 #endif 683 684 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 685 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 686 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 687 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 688 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 689 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 690 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 691 692 static inline unsigned long get_lock_parent_ip(void) 693 { 694 unsigned long addr = CALLER_ADDR0; 695 696 if (!in_lock_functions(addr)) 697 return addr; 698 addr = CALLER_ADDR1; 699 if (!in_lock_functions(addr)) 700 return addr; 701 return CALLER_ADDR2; 702 } 703 704 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE 705 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 706 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 707 #else 708 /* 709 * Use defines instead of static inlines because some arches will make code out 710 * of the CALLER_ADDR, when we really want these to be a real nop. 711 */ 712 # define trace_preempt_on(a0, a1) do { } while (0) 713 # define trace_preempt_off(a0, a1) do { } while (0) 714 #endif 715 716 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 717 extern void ftrace_init(void); 718 #else 719 static inline void ftrace_init(void) { } 720 #endif 721 722 /* 723 * Structure that defines an entry function trace. 724 * It's already packed but the attribute "packed" is needed 725 * to remove extra padding at the end. 726 */ 727 struct ftrace_graph_ent { 728 unsigned long func; /* Current function */ 729 int depth; 730 } __packed; 731 732 /* 733 * Structure that defines a return function trace. 734 * It's already packed but the attribute "packed" is needed 735 * to remove extra padding at the end. 736 */ 737 struct ftrace_graph_ret { 738 unsigned long func; /* Current function */ 739 /* Number of functions that overran the depth limit for current task */ 740 unsigned long overrun; 741 unsigned long long calltime; 742 unsigned long long rettime; 743 int depth; 744 } __packed; 745 746 /* Type of the callback handlers for tracing function graph*/ 747 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 748 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 749 750 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 751 752 /* 753 * Stack of return addresses for functions 754 * of a thread. 755 * Used in struct thread_info 756 */ 757 struct ftrace_ret_stack { 758 unsigned long ret; 759 unsigned long func; 760 unsigned long long calltime; 761 #ifdef CONFIG_FUNCTION_PROFILER 762 unsigned long long subtime; 763 #endif 764 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 765 unsigned long fp; 766 #endif 767 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 768 unsigned long *retp; 769 #endif 770 }; 771 772 /* 773 * Primary handler of a function return. 774 * It relays on ftrace_return_to_handler. 775 * Defined in entry_32/64.S 776 */ 777 extern void return_to_handler(void); 778 779 extern int 780 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 781 unsigned long frame_pointer, unsigned long *retp); 782 783 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 784 unsigned long ret, unsigned long *retp); 785 786 /* 787 * Sometimes we don't want to trace a function with the function 788 * graph tracer but we want them to keep traced by the usual function 789 * tracer if the function graph tracer is not configured. 790 */ 791 #define __notrace_funcgraph notrace 792 793 #define FTRACE_NOTRACE_DEPTH 65536 794 #define FTRACE_RETFUNC_DEPTH 50 795 #define FTRACE_RETSTACK_ALLOC_SIZE 32 796 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 797 trace_func_graph_ent_t entryfunc); 798 799 extern bool ftrace_graph_is_dead(void); 800 extern void ftrace_graph_stop(void); 801 802 /* The current handlers in use */ 803 extern trace_func_graph_ret_t ftrace_graph_return; 804 extern trace_func_graph_ent_t ftrace_graph_entry; 805 806 extern void unregister_ftrace_graph(void); 807 808 extern void ftrace_graph_init_task(struct task_struct *t); 809 extern void ftrace_graph_exit_task(struct task_struct *t); 810 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 811 812 static inline int task_curr_ret_stack(struct task_struct *t) 813 { 814 return t->curr_ret_stack; 815 } 816 817 static inline void pause_graph_tracing(void) 818 { 819 atomic_inc(¤t->tracing_graph_pause); 820 } 821 822 static inline void unpause_graph_tracing(void) 823 { 824 atomic_dec(¤t->tracing_graph_pause); 825 } 826 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 827 828 #define __notrace_funcgraph 829 830 static inline void ftrace_graph_init_task(struct task_struct *t) { } 831 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 832 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 833 834 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 835 trace_func_graph_ent_t entryfunc) 836 { 837 return -1; 838 } 839 static inline void unregister_ftrace_graph(void) { } 840 841 static inline int task_curr_ret_stack(struct task_struct *tsk) 842 { 843 return -1; 844 } 845 846 static inline unsigned long 847 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 848 unsigned long *retp) 849 { 850 return ret; 851 } 852 853 static inline void pause_graph_tracing(void) { } 854 static inline void unpause_graph_tracing(void) { } 855 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 856 857 #ifdef CONFIG_TRACING 858 859 /* flags for current->trace */ 860 enum { 861 TSK_TRACE_FL_TRACE_BIT = 0, 862 TSK_TRACE_FL_GRAPH_BIT = 1, 863 }; 864 enum { 865 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 866 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 867 }; 868 869 static inline void set_tsk_trace_trace(struct task_struct *tsk) 870 { 871 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 872 } 873 874 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 875 { 876 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 877 } 878 879 static inline int test_tsk_trace_trace(struct task_struct *tsk) 880 { 881 return tsk->trace & TSK_TRACE_FL_TRACE; 882 } 883 884 static inline void set_tsk_trace_graph(struct task_struct *tsk) 885 { 886 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 887 } 888 889 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 890 { 891 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 892 } 893 894 static inline int test_tsk_trace_graph(struct task_struct *tsk) 895 { 896 return tsk->trace & TSK_TRACE_FL_GRAPH; 897 } 898 899 enum ftrace_dump_mode; 900 901 extern enum ftrace_dump_mode ftrace_dump_on_oops; 902 extern int tracepoint_printk; 903 904 extern void disable_trace_on_warning(void); 905 extern int __disable_trace_on_warning; 906 907 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 908 void __user *buffer, size_t *lenp, 909 loff_t *ppos); 910 911 #else /* CONFIG_TRACING */ 912 static inline void disable_trace_on_warning(void) { } 913 #endif /* CONFIG_TRACING */ 914 915 #ifdef CONFIG_FTRACE_SYSCALLS 916 917 unsigned long arch_syscall_addr(int nr); 918 919 #endif /* CONFIG_FTRACE_SYSCALLS */ 920 921 #endif /* _LINUX_FTRACE_H */ 922