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 44 void trace_init(void); 45 #else 46 static inline void trace_init(void) { } 47 #endif 48 49 struct module; 50 struct ftrace_hash; 51 52 #ifdef CONFIG_FUNCTION_TRACER 53 54 extern int ftrace_enabled; 55 extern int 56 ftrace_enable_sysctl(struct ctl_table *table, int write, 57 void __user *buffer, size_t *lenp, 58 loff_t *ppos); 59 60 struct ftrace_ops; 61 62 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 63 struct ftrace_ops *op, struct pt_regs *regs); 64 65 ftrace_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 */ 120 enum { 121 FTRACE_OPS_FL_ENABLED = 1 << 0, 122 FTRACE_OPS_FL_DYNAMIC = 1 << 1, 123 FTRACE_OPS_FL_CONTROL = 1 << 2, 124 FTRACE_OPS_FL_SAVE_REGS = 1 << 3, 125 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 4, 126 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 5, 127 FTRACE_OPS_FL_STUB = 1 << 6, 128 FTRACE_OPS_FL_INITIALIZED = 1 << 7, 129 FTRACE_OPS_FL_DELETED = 1 << 8, 130 FTRACE_OPS_FL_ADDING = 1 << 9, 131 FTRACE_OPS_FL_REMOVING = 1 << 10, 132 FTRACE_OPS_FL_MODIFYING = 1 << 11, 133 FTRACE_OPS_FL_ALLOC_TRAMP = 1 << 12, 134 FTRACE_OPS_FL_IPMODIFY = 1 << 13, 135 }; 136 137 #ifdef CONFIG_DYNAMIC_FTRACE 138 /* The hash used to know what functions callbacks trace */ 139 struct ftrace_ops_hash { 140 struct ftrace_hash *notrace_hash; 141 struct ftrace_hash *filter_hash; 142 struct mutex regex_lock; 143 }; 144 #endif 145 146 /* 147 * Note, ftrace_ops can be referenced outside of RCU protection. 148 * (Although, for perf, the control ops prevent that). If ftrace_ops is 149 * allocated and not part of kernel core data, the unregistering of it will 150 * perform a scheduling on all CPUs to make sure that there are no more users. 151 * Depending on the load of the system that may take a bit of time. 152 * 153 * Any private data added must also take care not to be freed and if private 154 * data is added to a ftrace_ops that is in core code, the user of the 155 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 156 */ 157 struct ftrace_ops { 158 ftrace_func_t func; 159 struct ftrace_ops *next; 160 unsigned long flags; 161 void *private; 162 int __percpu *disabled; 163 #ifdef CONFIG_DYNAMIC_FTRACE 164 int nr_trampolines; 165 struct ftrace_ops_hash local_hash; 166 struct ftrace_ops_hash *func_hash; 167 struct ftrace_ops_hash old_hash; 168 unsigned long trampoline; 169 unsigned long trampoline_size; 170 #endif 171 }; 172 173 /* 174 * Type of the current tracing. 175 */ 176 enum ftrace_tracing_type_t { 177 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 178 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 179 }; 180 181 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 182 extern enum ftrace_tracing_type_t ftrace_tracing_type; 183 184 /* 185 * The ftrace_ops must be a static and should also 186 * be read_mostly. These functions do modify read_mostly variables 187 * so use them sparely. Never free an ftrace_op or modify the 188 * next pointer after it has been registered. Even after unregistering 189 * it, the next pointer may still be used internally. 190 */ 191 int register_ftrace_function(struct ftrace_ops *ops); 192 int unregister_ftrace_function(struct ftrace_ops *ops); 193 void clear_ftrace_function(void); 194 195 /** 196 * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu 197 * 198 * This function enables tracing on current cpu by decreasing 199 * the per cpu control variable. 200 * It must be called with preemption disabled and only on ftrace_ops 201 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 202 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 203 */ 204 static inline void ftrace_function_local_enable(struct ftrace_ops *ops) 205 { 206 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 207 return; 208 209 (*this_cpu_ptr(ops->disabled))--; 210 } 211 212 /** 213 * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu 214 * 215 * This function enables tracing on current cpu by decreasing 216 * the per cpu control variable. 217 * It must be called with preemption disabled and only on ftrace_ops 218 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 219 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 220 */ 221 static inline void ftrace_function_local_disable(struct ftrace_ops *ops) 222 { 223 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 224 return; 225 226 (*this_cpu_ptr(ops->disabled))++; 227 } 228 229 /** 230 * ftrace_function_local_disabled - returns ftrace_ops disabled value 231 * on current cpu 232 * 233 * This function returns value of ftrace_ops::disabled on current cpu. 234 * It must be called with preemption disabled and only on ftrace_ops 235 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 236 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 237 */ 238 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) 239 { 240 WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)); 241 return *this_cpu_ptr(ops->disabled); 242 } 243 244 extern void ftrace_stub(unsigned long a0, unsigned long a1, 245 struct ftrace_ops *op, struct pt_regs *regs); 246 247 #else /* !CONFIG_FUNCTION_TRACER */ 248 /* 249 * (un)register_ftrace_function must be a macro since the ops parameter 250 * must not be evaluated. 251 */ 252 #define register_ftrace_function(ops) ({ 0; }) 253 #define unregister_ftrace_function(ops) ({ 0; }) 254 static inline int ftrace_nr_registered_ops(void) 255 { 256 return 0; 257 } 258 static inline void clear_ftrace_function(void) { } 259 static inline void ftrace_kill(void) { } 260 #endif /* CONFIG_FUNCTION_TRACER */ 261 262 #ifdef CONFIG_STACK_TRACER 263 extern int stack_tracer_enabled; 264 int 265 stack_trace_sysctl(struct ctl_table *table, int write, 266 void __user *buffer, size_t *lenp, 267 loff_t *ppos); 268 #endif 269 270 struct ftrace_func_command { 271 struct list_head list; 272 char *name; 273 int (*func)(struct ftrace_hash *hash, 274 char *func, char *cmd, 275 char *params, int enable); 276 }; 277 278 #ifdef CONFIG_DYNAMIC_FTRACE 279 280 int ftrace_arch_code_modify_prepare(void); 281 int ftrace_arch_code_modify_post_process(void); 282 283 struct dyn_ftrace; 284 285 void ftrace_bug(int err, struct dyn_ftrace *rec); 286 287 struct seq_file; 288 289 struct ftrace_probe_ops { 290 void (*func)(unsigned long ip, 291 unsigned long parent_ip, 292 void **data); 293 int (*init)(struct ftrace_probe_ops *ops, 294 unsigned long ip, void **data); 295 void (*free)(struct ftrace_probe_ops *ops, 296 unsigned long ip, void **data); 297 int (*print)(struct seq_file *m, 298 unsigned long ip, 299 struct ftrace_probe_ops *ops, 300 void *data); 301 }; 302 303 extern int 304 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 305 void *data); 306 extern void 307 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 308 void *data); 309 extern void 310 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops); 311 extern void unregister_ftrace_function_probe_all(char *glob); 312 313 extern int ftrace_text_reserved(const void *start, const void *end); 314 315 extern int ftrace_nr_registered_ops(void); 316 317 bool is_ftrace_trampoline(unsigned long addr); 318 319 /* 320 * The dyn_ftrace record's flags field is split into two parts. 321 * the first part which is '0-FTRACE_REF_MAX' is a counter of 322 * the number of callbacks that have registered the function that 323 * the dyn_ftrace descriptor represents. 324 * 325 * The second part is a mask: 326 * ENABLED - the function is being traced 327 * REGS - the record wants the function to save regs 328 * REGS_EN - the function is set up to save regs. 329 * IPMODIFY - the record allows for the IP address to be changed. 330 * 331 * When a new ftrace_ops is registered and wants a function to save 332 * pt_regs, the rec->flag REGS is set. When the function has been 333 * set up to save regs, the REG_EN flag is set. Once a function 334 * starts saving regs it will do so until all ftrace_ops are removed 335 * from tracing that function. 336 */ 337 enum { 338 FTRACE_FL_ENABLED = (1UL << 31), 339 FTRACE_FL_REGS = (1UL << 30), 340 FTRACE_FL_REGS_EN = (1UL << 29), 341 FTRACE_FL_TRAMP = (1UL << 28), 342 FTRACE_FL_TRAMP_EN = (1UL << 27), 343 FTRACE_FL_IPMODIFY = (1UL << 26), 344 }; 345 346 #define FTRACE_REF_MAX_SHIFT 26 347 #define FTRACE_FL_BITS 6 348 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 349 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 350 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 351 352 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 353 354 struct dyn_ftrace { 355 unsigned long ip; /* address of mcount call-site */ 356 unsigned long flags; 357 struct dyn_arch_ftrace arch; 358 }; 359 360 int ftrace_force_update(void); 361 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 362 int remove, int reset); 363 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 364 int len, int reset); 365 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 366 int len, int reset); 367 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 368 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 369 void ftrace_free_filter(struct ftrace_ops *ops); 370 371 int register_ftrace_command(struct ftrace_func_command *cmd); 372 int unregister_ftrace_command(struct ftrace_func_command *cmd); 373 374 enum { 375 FTRACE_UPDATE_CALLS = (1 << 0), 376 FTRACE_DISABLE_CALLS = (1 << 1), 377 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 378 FTRACE_START_FUNC_RET = (1 << 3), 379 FTRACE_STOP_FUNC_RET = (1 << 4), 380 }; 381 382 /* 383 * The FTRACE_UPDATE_* enum is used to pass information back 384 * from the ftrace_update_record() and ftrace_test_record() 385 * functions. These are called by the code update routines 386 * to find out what is to be done for a given function. 387 * 388 * IGNORE - The function is already what we want it to be 389 * MAKE_CALL - Start tracing the function 390 * MODIFY_CALL - Stop saving regs for the function 391 * MAKE_NOP - Stop tracing the function 392 */ 393 enum { 394 FTRACE_UPDATE_IGNORE, 395 FTRACE_UPDATE_MAKE_CALL, 396 FTRACE_UPDATE_MODIFY_CALL, 397 FTRACE_UPDATE_MAKE_NOP, 398 }; 399 400 enum { 401 FTRACE_ITER_FILTER = (1 << 0), 402 FTRACE_ITER_NOTRACE = (1 << 1), 403 FTRACE_ITER_PRINTALL = (1 << 2), 404 FTRACE_ITER_DO_HASH = (1 << 3), 405 FTRACE_ITER_HASH = (1 << 4), 406 FTRACE_ITER_ENABLED = (1 << 5), 407 }; 408 409 void arch_ftrace_update_code(int command); 410 411 struct ftrace_rec_iter; 412 413 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 414 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 415 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 416 417 #define for_ftrace_rec_iter(iter) \ 418 for (iter = ftrace_rec_iter_start(); \ 419 iter; \ 420 iter = ftrace_rec_iter_next(iter)) 421 422 423 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 424 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 425 void ftrace_run_stop_machine(int command); 426 unsigned long ftrace_location(unsigned long ip); 427 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 428 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 429 430 extern ftrace_func_t ftrace_trace_function; 431 432 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 433 struct inode *inode, struct file *file); 434 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 435 size_t cnt, loff_t *ppos); 436 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 437 size_t cnt, loff_t *ppos); 438 int ftrace_regex_release(struct inode *inode, struct file *file); 439 440 void __init 441 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 442 443 /* defined in arch */ 444 extern int ftrace_ip_converted(unsigned long ip); 445 extern int ftrace_dyn_arch_init(void); 446 extern void ftrace_replace_code(int enable); 447 extern int ftrace_update_ftrace_func(ftrace_func_t func); 448 extern void ftrace_caller(void); 449 extern void ftrace_regs_caller(void); 450 extern void ftrace_call(void); 451 extern void ftrace_regs_call(void); 452 extern void mcount_call(void); 453 454 void ftrace_modify_all_code(int command); 455 456 #ifndef FTRACE_ADDR 457 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 458 #endif 459 460 #ifndef FTRACE_GRAPH_ADDR 461 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 462 #endif 463 464 #ifndef FTRACE_REGS_ADDR 465 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 466 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 467 #else 468 # define FTRACE_REGS_ADDR FTRACE_ADDR 469 #endif 470 #endif 471 472 /* 473 * If an arch would like functions that are only traced 474 * by the function graph tracer to jump directly to its own 475 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 476 * to be that address to jump to. 477 */ 478 #ifndef FTRACE_GRAPH_TRAMP_ADDR 479 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 480 #endif 481 482 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 483 extern void ftrace_graph_caller(void); 484 extern int ftrace_enable_ftrace_graph_caller(void); 485 extern int ftrace_disable_ftrace_graph_caller(void); 486 #else 487 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 488 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 489 #endif 490 491 /** 492 * ftrace_make_nop - convert code into nop 493 * @mod: module structure if called by module load initialization 494 * @rec: the mcount call site record 495 * @addr: the address that the call site should be calling 496 * 497 * This is a very sensitive operation and great care needs 498 * to be taken by the arch. The operation should carefully 499 * read the location, check to see if what is read is indeed 500 * what we expect it to be, and then on success of the compare, 501 * it should write to the location. 502 * 503 * The code segment at @rec->ip should be a caller to @addr 504 * 505 * Return must be: 506 * 0 on success 507 * -EFAULT on error reading the location 508 * -EINVAL on a failed compare of the contents 509 * -EPERM on error writing to the location 510 * Any other value will be considered a failure. 511 */ 512 extern int ftrace_make_nop(struct module *mod, 513 struct dyn_ftrace *rec, unsigned long addr); 514 515 /** 516 * ftrace_make_call - convert a nop call site into a call to addr 517 * @rec: the mcount call site record 518 * @addr: the address that the call site should call 519 * 520 * This is a very sensitive operation and great care needs 521 * to be taken by the arch. The operation should carefully 522 * read the location, check to see if what is read is indeed 523 * what we expect it to be, and then on success of the compare, 524 * it should write to the location. 525 * 526 * The code segment at @rec->ip should be a nop 527 * 528 * Return must be: 529 * 0 on success 530 * -EFAULT on error reading the location 531 * -EINVAL on a failed compare of the contents 532 * -EPERM on error writing to the location 533 * Any other value will be considered a failure. 534 */ 535 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 536 537 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 538 /** 539 * ftrace_modify_call - convert from one addr to another (no nop) 540 * @rec: the mcount call site record 541 * @old_addr: the address expected to be currently called to 542 * @addr: the address to change to 543 * 544 * This is a very sensitive operation and great care needs 545 * to be taken by the arch. The operation should carefully 546 * read the location, check to see if what is read is indeed 547 * what we expect it to be, and then on success of the compare, 548 * it should write to the location. 549 * 550 * The code segment at @rec->ip should be a caller to @old_addr 551 * 552 * Return must be: 553 * 0 on success 554 * -EFAULT on error reading the location 555 * -EINVAL on a failed compare of the contents 556 * -EPERM on error writing to the location 557 * Any other value will be considered a failure. 558 */ 559 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 560 unsigned long addr); 561 #else 562 /* Should never be called */ 563 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 564 unsigned long addr) 565 { 566 return -EINVAL; 567 } 568 #endif 569 570 /* May be defined in arch */ 571 extern int ftrace_arch_read_dyn_info(char *buf, int size); 572 573 extern int skip_trace(unsigned long ip); 574 extern void ftrace_module_init(struct module *mod); 575 576 extern void ftrace_disable_daemon(void); 577 extern void ftrace_enable_daemon(void); 578 #else /* CONFIG_DYNAMIC_FTRACE */ 579 static inline int skip_trace(unsigned long ip) { return 0; } 580 static inline int ftrace_force_update(void) { return 0; } 581 static inline void ftrace_disable_daemon(void) { } 582 static inline void ftrace_enable_daemon(void) { } 583 static inline void ftrace_release_mod(struct module *mod) {} 584 static inline void ftrace_module_init(struct module *mod) {} 585 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd) 586 { 587 return -EINVAL; 588 } 589 static inline __init int unregister_ftrace_command(char *cmd_name) 590 { 591 return -EINVAL; 592 } 593 static inline int ftrace_text_reserved(const void *start, const void *end) 594 { 595 return 0; 596 } 597 static inline unsigned long ftrace_location(unsigned long ip) 598 { 599 return 0; 600 } 601 602 /* 603 * Again users of functions that have ftrace_ops may not 604 * have them defined when ftrace is not enabled, but these 605 * functions may still be called. Use a macro instead of inline. 606 */ 607 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 608 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 609 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 610 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 611 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 612 #define ftrace_free_filter(ops) do { } while (0) 613 614 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 615 size_t cnt, loff_t *ppos) { return -ENODEV; } 616 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 617 size_t cnt, loff_t *ppos) { return -ENODEV; } 618 static inline int 619 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 620 621 static inline bool is_ftrace_trampoline(unsigned long addr) 622 { 623 return false; 624 } 625 #endif /* CONFIG_DYNAMIC_FTRACE */ 626 627 /* totally disable ftrace - can not re-enable after this */ 628 void ftrace_kill(void); 629 630 static inline void tracer_disable(void) 631 { 632 #ifdef CONFIG_FUNCTION_TRACER 633 ftrace_enabled = 0; 634 #endif 635 } 636 637 /* 638 * Ftrace disable/restore without lock. Some synchronization mechanism 639 * must be used to prevent ftrace_enabled to be changed between 640 * disable/restore. 641 */ 642 static inline int __ftrace_enabled_save(void) 643 { 644 #ifdef CONFIG_FUNCTION_TRACER 645 int saved_ftrace_enabled = ftrace_enabled; 646 ftrace_enabled = 0; 647 return saved_ftrace_enabled; 648 #else 649 return 0; 650 #endif 651 } 652 653 static inline void __ftrace_enabled_restore(int enabled) 654 { 655 #ifdef CONFIG_FUNCTION_TRACER 656 ftrace_enabled = enabled; 657 #endif 658 } 659 660 /* All archs should have this, but we define it for consistency */ 661 #ifndef ftrace_return_address0 662 # define ftrace_return_address0 __builtin_return_address(0) 663 #endif 664 665 /* Archs may use other ways for ADDR1 and beyond */ 666 #ifndef ftrace_return_address 667 # ifdef CONFIG_FRAME_POINTER 668 # define ftrace_return_address(n) __builtin_return_address(n) 669 # else 670 # define ftrace_return_address(n) 0UL 671 # endif 672 #endif 673 674 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 675 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 676 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 677 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 678 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 679 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 680 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 681 682 #ifdef CONFIG_IRQSOFF_TRACER 683 extern void time_hardirqs_on(unsigned long a0, unsigned long a1); 684 extern void time_hardirqs_off(unsigned long a0, unsigned long a1); 685 #else 686 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } 687 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } 688 #endif 689 690 #ifdef CONFIG_PREEMPT_TRACER 691 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 692 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 693 #else 694 /* 695 * Use defines instead of static inlines because some arches will make code out 696 * of the CALLER_ADDR, when we really want these to be a real nop. 697 */ 698 # define trace_preempt_on(a0, a1) do { } while (0) 699 # define trace_preempt_off(a0, a1) do { } while (0) 700 #endif 701 702 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 703 extern void ftrace_init(void); 704 #else 705 static inline void ftrace_init(void) { } 706 #endif 707 708 /* 709 * Structure that defines an entry function trace. 710 */ 711 struct ftrace_graph_ent { 712 unsigned long func; /* Current function */ 713 int depth; 714 }; 715 716 /* 717 * Structure that defines a return function trace. 718 */ 719 struct ftrace_graph_ret { 720 unsigned long func; /* Current function */ 721 unsigned long long calltime; 722 unsigned long long rettime; 723 /* Number of functions that overran the depth limit for current task */ 724 unsigned long overrun; 725 int depth; 726 }; 727 728 /* Type of the callback handlers for tracing function graph*/ 729 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 730 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 731 732 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 733 734 /* for init task */ 735 #define INIT_FTRACE_GRAPH .ret_stack = NULL, 736 737 /* 738 * Stack of return addresses for functions 739 * of a thread. 740 * Used in struct thread_info 741 */ 742 struct ftrace_ret_stack { 743 unsigned long ret; 744 unsigned long func; 745 unsigned long long calltime; 746 unsigned long long subtime; 747 unsigned long fp; 748 }; 749 750 /* 751 * Primary handler of a function return. 752 * It relays on ftrace_return_to_handler. 753 * Defined in entry_32/64.S 754 */ 755 extern void return_to_handler(void); 756 757 extern int 758 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 759 unsigned long frame_pointer); 760 761 /* 762 * Sometimes we don't want to trace a function with the function 763 * graph tracer but we want them to keep traced by the usual function 764 * tracer if the function graph tracer is not configured. 765 */ 766 #define __notrace_funcgraph notrace 767 768 /* 769 * We want to which function is an entrypoint of a hardirq. 770 * That will help us to put a signal on output. 771 */ 772 #define __irq_entry __attribute__((__section__(".irqentry.text"))) 773 774 /* Limits of hardirq entrypoints */ 775 extern char __irqentry_text_start[]; 776 extern char __irqentry_text_end[]; 777 778 #define FTRACE_NOTRACE_DEPTH 65536 779 #define FTRACE_RETFUNC_DEPTH 50 780 #define FTRACE_RETSTACK_ALLOC_SIZE 32 781 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 782 trace_func_graph_ent_t entryfunc); 783 784 extern bool ftrace_graph_is_dead(void); 785 extern void ftrace_graph_stop(void); 786 787 /* The current handlers in use */ 788 extern trace_func_graph_ret_t ftrace_graph_return; 789 extern trace_func_graph_ent_t ftrace_graph_entry; 790 791 extern void unregister_ftrace_graph(void); 792 793 extern void ftrace_graph_init_task(struct task_struct *t); 794 extern void ftrace_graph_exit_task(struct task_struct *t); 795 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 796 797 static inline int task_curr_ret_stack(struct task_struct *t) 798 { 799 return t->curr_ret_stack; 800 } 801 802 static inline void pause_graph_tracing(void) 803 { 804 atomic_inc(¤t->tracing_graph_pause); 805 } 806 807 static inline void unpause_graph_tracing(void) 808 { 809 atomic_dec(¤t->tracing_graph_pause); 810 } 811 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 812 813 #define __notrace_funcgraph 814 #define __irq_entry 815 #define INIT_FTRACE_GRAPH 816 817 static inline void ftrace_graph_init_task(struct task_struct *t) { } 818 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 819 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 820 821 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 822 trace_func_graph_ent_t entryfunc) 823 { 824 return -1; 825 } 826 static inline void unregister_ftrace_graph(void) { } 827 828 static inline int task_curr_ret_stack(struct task_struct *tsk) 829 { 830 return -1; 831 } 832 833 static inline void pause_graph_tracing(void) { } 834 static inline void unpause_graph_tracing(void) { } 835 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 836 837 #ifdef CONFIG_TRACING 838 839 /* flags for current->trace */ 840 enum { 841 TSK_TRACE_FL_TRACE_BIT = 0, 842 TSK_TRACE_FL_GRAPH_BIT = 1, 843 }; 844 enum { 845 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 846 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 847 }; 848 849 static inline void set_tsk_trace_trace(struct task_struct *tsk) 850 { 851 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 852 } 853 854 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 855 { 856 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 857 } 858 859 static inline int test_tsk_trace_trace(struct task_struct *tsk) 860 { 861 return tsk->trace & TSK_TRACE_FL_TRACE; 862 } 863 864 static inline void set_tsk_trace_graph(struct task_struct *tsk) 865 { 866 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 867 } 868 869 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 870 { 871 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 872 } 873 874 static inline int test_tsk_trace_graph(struct task_struct *tsk) 875 { 876 return tsk->trace & TSK_TRACE_FL_GRAPH; 877 } 878 879 enum ftrace_dump_mode; 880 881 extern enum ftrace_dump_mode ftrace_dump_on_oops; 882 extern int tracepoint_printk; 883 884 extern void disable_trace_on_warning(void); 885 extern int __disable_trace_on_warning; 886 887 #ifdef CONFIG_PREEMPT 888 #define INIT_TRACE_RECURSION .trace_recursion = 0, 889 #endif 890 891 #else /* CONFIG_TRACING */ 892 static inline void disable_trace_on_warning(void) { } 893 #endif /* CONFIG_TRACING */ 894 895 #ifndef INIT_TRACE_RECURSION 896 #define INIT_TRACE_RECURSION 897 #endif 898 899 #ifdef CONFIG_FTRACE_SYSCALLS 900 901 unsigned long arch_syscall_addr(int nr); 902 903 #endif /* CONFIG_FTRACE_SYSCALLS */ 904 905 #endif /* _LINUX_FTRACE_H */ 906