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 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 120 */ 121 enum { 122 FTRACE_OPS_FL_ENABLED = 1 << 0, 123 FTRACE_OPS_FL_DYNAMIC = 1 << 1, 124 FTRACE_OPS_FL_CONTROL = 1 << 2, 125 FTRACE_OPS_FL_SAVE_REGS = 1 << 3, 126 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 4, 127 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 5, 128 FTRACE_OPS_FL_STUB = 1 << 6, 129 FTRACE_OPS_FL_INITIALIZED = 1 << 7, 130 FTRACE_OPS_FL_DELETED = 1 << 8, 131 FTRACE_OPS_FL_ADDING = 1 << 9, 132 FTRACE_OPS_FL_REMOVING = 1 << 10, 133 FTRACE_OPS_FL_MODIFYING = 1 << 11, 134 FTRACE_OPS_FL_ALLOC_TRAMP = 1 << 12, 135 FTRACE_OPS_FL_IPMODIFY = 1 << 13, 136 FTRACE_OPS_FL_PID = 1 << 14, 137 }; 138 139 #ifdef CONFIG_DYNAMIC_FTRACE 140 /* The hash used to know what functions callbacks trace */ 141 struct ftrace_ops_hash { 142 struct ftrace_hash *notrace_hash; 143 struct ftrace_hash *filter_hash; 144 struct mutex regex_lock; 145 }; 146 #endif 147 148 /* 149 * Note, ftrace_ops can be referenced outside of RCU protection. 150 * (Although, for perf, the control ops prevent that). If ftrace_ops is 151 * allocated and not part of kernel core data, the unregistering of it will 152 * perform a scheduling on all CPUs to make sure that there are no more users. 153 * Depending on the load of the system that may take a bit of time. 154 * 155 * Any private data added must also take care not to be freed and if private 156 * data is added to a ftrace_ops that is in core code, the user of the 157 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 158 */ 159 struct ftrace_ops { 160 ftrace_func_t func; 161 struct ftrace_ops *next; 162 unsigned long flags; 163 void *private; 164 ftrace_func_t saved_func; 165 int __percpu *disabled; 166 #ifdef CONFIG_DYNAMIC_FTRACE 167 int nr_trampolines; 168 struct ftrace_ops_hash local_hash; 169 struct ftrace_ops_hash *func_hash; 170 struct ftrace_ops_hash old_hash; 171 unsigned long trampoline; 172 unsigned long trampoline_size; 173 #endif 174 }; 175 176 /* 177 * Type of the current tracing. 178 */ 179 enum ftrace_tracing_type_t { 180 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 181 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 182 }; 183 184 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 185 extern enum ftrace_tracing_type_t ftrace_tracing_type; 186 187 /* 188 * The ftrace_ops must be a static and should also 189 * be read_mostly. These functions do modify read_mostly variables 190 * so use them sparely. Never free an ftrace_op or modify the 191 * next pointer after it has been registered. Even after unregistering 192 * it, the next pointer may still be used internally. 193 */ 194 int register_ftrace_function(struct ftrace_ops *ops); 195 int unregister_ftrace_function(struct ftrace_ops *ops); 196 void clear_ftrace_function(void); 197 198 /** 199 * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu 200 * 201 * This function enables tracing on current cpu by decreasing 202 * the per cpu control variable. 203 * It must be called with preemption disabled and only on ftrace_ops 204 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 205 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 206 */ 207 static inline void ftrace_function_local_enable(struct ftrace_ops *ops) 208 { 209 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 210 return; 211 212 (*this_cpu_ptr(ops->disabled))--; 213 } 214 215 /** 216 * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu 217 * 218 * This function enables tracing on current cpu by decreasing 219 * the per cpu control variable. 220 * It must be called with preemption disabled and only on ftrace_ops 221 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 222 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 223 */ 224 static inline void ftrace_function_local_disable(struct ftrace_ops *ops) 225 { 226 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 227 return; 228 229 (*this_cpu_ptr(ops->disabled))++; 230 } 231 232 /** 233 * ftrace_function_local_disabled - returns ftrace_ops disabled value 234 * on current cpu 235 * 236 * This function returns value of ftrace_ops::disabled on current cpu. 237 * It must be called with preemption disabled and only on ftrace_ops 238 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 239 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 240 */ 241 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) 242 { 243 WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)); 244 return *this_cpu_ptr(ops->disabled); 245 } 246 247 extern void ftrace_stub(unsigned long a0, unsigned long a1, 248 struct ftrace_ops *op, struct pt_regs *regs); 249 250 #else /* !CONFIG_FUNCTION_TRACER */ 251 /* 252 * (un)register_ftrace_function must be a macro since the ops parameter 253 * must not be evaluated. 254 */ 255 #define register_ftrace_function(ops) ({ 0; }) 256 #define unregister_ftrace_function(ops) ({ 0; }) 257 static inline int ftrace_nr_registered_ops(void) 258 { 259 return 0; 260 } 261 static inline void clear_ftrace_function(void) { } 262 static inline void ftrace_kill(void) { } 263 #endif /* CONFIG_FUNCTION_TRACER */ 264 265 #ifdef CONFIG_STACK_TRACER 266 extern int stack_tracer_enabled; 267 int 268 stack_trace_sysctl(struct ctl_table *table, int write, 269 void __user *buffer, size_t *lenp, 270 loff_t *ppos); 271 #endif 272 273 struct ftrace_func_command { 274 struct list_head list; 275 char *name; 276 int (*func)(struct ftrace_hash *hash, 277 char *func, char *cmd, 278 char *params, int enable); 279 }; 280 281 #ifdef CONFIG_DYNAMIC_FTRACE 282 283 int ftrace_arch_code_modify_prepare(void); 284 int ftrace_arch_code_modify_post_process(void); 285 286 struct dyn_ftrace; 287 288 void ftrace_bug(int err, struct dyn_ftrace *rec); 289 290 struct seq_file; 291 292 struct ftrace_probe_ops { 293 void (*func)(unsigned long ip, 294 unsigned long parent_ip, 295 void **data); 296 int (*init)(struct ftrace_probe_ops *ops, 297 unsigned long ip, void **data); 298 void (*free)(struct ftrace_probe_ops *ops, 299 unsigned long ip, void **data); 300 int (*print)(struct seq_file *m, 301 unsigned long ip, 302 struct ftrace_probe_ops *ops, 303 void *data); 304 }; 305 306 extern int 307 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 308 void *data); 309 extern void 310 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 311 void *data); 312 extern void 313 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops); 314 extern void unregister_ftrace_function_probe_all(char *glob); 315 316 extern int ftrace_text_reserved(const void *start, const void *end); 317 318 extern int ftrace_nr_registered_ops(void); 319 320 bool is_ftrace_trampoline(unsigned long addr); 321 322 /* 323 * The dyn_ftrace record's flags field is split into two parts. 324 * the first part which is '0-FTRACE_REF_MAX' is a counter of 325 * the number of callbacks that have registered the function that 326 * the dyn_ftrace descriptor represents. 327 * 328 * The second part is a mask: 329 * ENABLED - the function is being traced 330 * REGS - the record wants the function to save regs 331 * REGS_EN - the function is set up to save regs. 332 * IPMODIFY - the record allows for the IP address to be changed. 333 * 334 * When a new ftrace_ops is registered and wants a function to save 335 * pt_regs, the rec->flag REGS is set. When the function has been 336 * set up to save regs, the REG_EN flag is set. Once a function 337 * starts saving regs it will do so until all ftrace_ops are removed 338 * from tracing that function. 339 */ 340 enum { 341 FTRACE_FL_ENABLED = (1UL << 31), 342 FTRACE_FL_REGS = (1UL << 30), 343 FTRACE_FL_REGS_EN = (1UL << 29), 344 FTRACE_FL_TRAMP = (1UL << 28), 345 FTRACE_FL_TRAMP_EN = (1UL << 27), 346 FTRACE_FL_IPMODIFY = (1UL << 26), 347 }; 348 349 #define FTRACE_REF_MAX_SHIFT 26 350 #define FTRACE_FL_BITS 6 351 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 352 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 353 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 354 355 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 356 357 struct dyn_ftrace { 358 unsigned long ip; /* address of mcount call-site */ 359 unsigned long flags; 360 struct dyn_arch_ftrace arch; 361 }; 362 363 int ftrace_force_update(void); 364 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 365 int remove, int reset); 366 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 367 int len, int reset); 368 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 369 int len, int reset); 370 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 371 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 372 void ftrace_free_filter(struct ftrace_ops *ops); 373 374 int register_ftrace_command(struct ftrace_func_command *cmd); 375 int unregister_ftrace_command(struct ftrace_func_command *cmd); 376 377 enum { 378 FTRACE_UPDATE_CALLS = (1 << 0), 379 FTRACE_DISABLE_CALLS = (1 << 1), 380 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 381 FTRACE_START_FUNC_RET = (1 << 3), 382 FTRACE_STOP_FUNC_RET = (1 << 4), 383 }; 384 385 /* 386 * The FTRACE_UPDATE_* enum is used to pass information back 387 * from the ftrace_update_record() and ftrace_test_record() 388 * functions. These are called by the code update routines 389 * to find out what is to be done for a given function. 390 * 391 * IGNORE - The function is already what we want it to be 392 * MAKE_CALL - Start tracing the function 393 * MODIFY_CALL - Stop saving regs for the function 394 * MAKE_NOP - Stop tracing the function 395 */ 396 enum { 397 FTRACE_UPDATE_IGNORE, 398 FTRACE_UPDATE_MAKE_CALL, 399 FTRACE_UPDATE_MODIFY_CALL, 400 FTRACE_UPDATE_MAKE_NOP, 401 }; 402 403 enum { 404 FTRACE_ITER_FILTER = (1 << 0), 405 FTRACE_ITER_NOTRACE = (1 << 1), 406 FTRACE_ITER_PRINTALL = (1 << 2), 407 FTRACE_ITER_DO_HASH = (1 << 3), 408 FTRACE_ITER_HASH = (1 << 4), 409 FTRACE_ITER_ENABLED = (1 << 5), 410 }; 411 412 void arch_ftrace_update_code(int command); 413 414 struct ftrace_rec_iter; 415 416 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 417 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 418 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 419 420 #define for_ftrace_rec_iter(iter) \ 421 for (iter = ftrace_rec_iter_start(); \ 422 iter; \ 423 iter = ftrace_rec_iter_next(iter)) 424 425 426 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 427 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 428 void ftrace_run_stop_machine(int command); 429 unsigned long ftrace_location(unsigned long ip); 430 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 431 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 432 433 extern ftrace_func_t ftrace_trace_function; 434 435 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 436 struct inode *inode, struct file *file); 437 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 438 size_t cnt, loff_t *ppos); 439 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 440 size_t cnt, loff_t *ppos); 441 int ftrace_regex_release(struct inode *inode, struct file *file); 442 443 void __init 444 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 445 446 /* defined in arch */ 447 extern int ftrace_ip_converted(unsigned long ip); 448 extern int ftrace_dyn_arch_init(void); 449 extern void ftrace_replace_code(int enable); 450 extern int ftrace_update_ftrace_func(ftrace_func_t func); 451 extern void ftrace_caller(void); 452 extern void ftrace_regs_caller(void); 453 extern void ftrace_call(void); 454 extern void ftrace_regs_call(void); 455 extern void mcount_call(void); 456 457 void ftrace_modify_all_code(int command); 458 459 #ifndef FTRACE_ADDR 460 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 461 #endif 462 463 #ifndef FTRACE_GRAPH_ADDR 464 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 465 #endif 466 467 #ifndef FTRACE_REGS_ADDR 468 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 469 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 470 #else 471 # define FTRACE_REGS_ADDR FTRACE_ADDR 472 #endif 473 #endif 474 475 /* 476 * If an arch would like functions that are only traced 477 * by the function graph tracer to jump directly to its own 478 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 479 * to be that address to jump to. 480 */ 481 #ifndef FTRACE_GRAPH_TRAMP_ADDR 482 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 483 #endif 484 485 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 486 extern void ftrace_graph_caller(void); 487 extern int ftrace_enable_ftrace_graph_caller(void); 488 extern int ftrace_disable_ftrace_graph_caller(void); 489 #else 490 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 491 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 492 #endif 493 494 /** 495 * ftrace_make_nop - convert code into nop 496 * @mod: module structure if called by module load initialization 497 * @rec: the mcount call site record 498 * @addr: the address that the call site should be calling 499 * 500 * This is a very sensitive operation and great care needs 501 * to be taken by the arch. The operation should carefully 502 * read the location, check to see if what is read is indeed 503 * what we expect it to be, and then on success of the compare, 504 * it should write to the location. 505 * 506 * The code segment at @rec->ip should be a caller to @addr 507 * 508 * Return must be: 509 * 0 on success 510 * -EFAULT on error reading the location 511 * -EINVAL on a failed compare of the contents 512 * -EPERM on error writing to the location 513 * Any other value will be considered a failure. 514 */ 515 extern int ftrace_make_nop(struct module *mod, 516 struct dyn_ftrace *rec, unsigned long addr); 517 518 /** 519 * ftrace_make_call - convert a nop call site into a call to addr 520 * @rec: the mcount call site record 521 * @addr: the address that the call site should call 522 * 523 * This is a very sensitive operation and great care needs 524 * to be taken by the arch. The operation should carefully 525 * read the location, check to see if what is read is indeed 526 * what we expect it to be, and then on success of the compare, 527 * it should write to the location. 528 * 529 * The code segment at @rec->ip should be a nop 530 * 531 * Return must be: 532 * 0 on success 533 * -EFAULT on error reading the location 534 * -EINVAL on a failed compare of the contents 535 * -EPERM on error writing to the location 536 * Any other value will be considered a failure. 537 */ 538 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 539 540 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 541 /** 542 * ftrace_modify_call - convert from one addr to another (no nop) 543 * @rec: the mcount call site record 544 * @old_addr: the address expected to be currently called to 545 * @addr: the address to change to 546 * 547 * This is a very sensitive operation and great care needs 548 * to be taken by the arch. The operation should carefully 549 * read the location, check to see if what is read is indeed 550 * what we expect it to be, and then on success of the compare, 551 * it should write to the location. 552 * 553 * The code segment at @rec->ip should be a caller to @old_addr 554 * 555 * Return must be: 556 * 0 on success 557 * -EFAULT on error reading the location 558 * -EINVAL on a failed compare of the contents 559 * -EPERM on error writing to the location 560 * Any other value will be considered a failure. 561 */ 562 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 563 unsigned long addr); 564 #else 565 /* Should never be called */ 566 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 567 unsigned long addr) 568 { 569 return -EINVAL; 570 } 571 #endif 572 573 /* May be defined in arch */ 574 extern int ftrace_arch_read_dyn_info(char *buf, int size); 575 576 extern int skip_trace(unsigned long ip); 577 extern void ftrace_module_init(struct module *mod); 578 579 extern void ftrace_disable_daemon(void); 580 extern void ftrace_enable_daemon(void); 581 #else /* CONFIG_DYNAMIC_FTRACE */ 582 static inline int skip_trace(unsigned long ip) { return 0; } 583 static inline int ftrace_force_update(void) { return 0; } 584 static inline void ftrace_disable_daemon(void) { } 585 static inline void ftrace_enable_daemon(void) { } 586 static inline void ftrace_release_mod(struct module *mod) {} 587 static inline void ftrace_module_init(struct module *mod) {} 588 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd) 589 { 590 return -EINVAL; 591 } 592 static inline __init int unregister_ftrace_command(char *cmd_name) 593 { 594 return -EINVAL; 595 } 596 static inline int ftrace_text_reserved(const void *start, const void *end) 597 { 598 return 0; 599 } 600 static inline unsigned long ftrace_location(unsigned long ip) 601 { 602 return 0; 603 } 604 605 /* 606 * Again users of functions that have ftrace_ops may not 607 * have them defined when ftrace is not enabled, but these 608 * functions may still be called. Use a macro instead of inline. 609 */ 610 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 611 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 612 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 613 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 614 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 615 #define ftrace_free_filter(ops) do { } while (0) 616 617 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 618 size_t cnt, loff_t *ppos) { return -ENODEV; } 619 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 620 size_t cnt, loff_t *ppos) { return -ENODEV; } 621 static inline int 622 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 623 624 static inline bool is_ftrace_trampoline(unsigned long addr) 625 { 626 return false; 627 } 628 #endif /* CONFIG_DYNAMIC_FTRACE */ 629 630 /* totally disable ftrace - can not re-enable after this */ 631 void ftrace_kill(void); 632 633 static inline void tracer_disable(void) 634 { 635 #ifdef CONFIG_FUNCTION_TRACER 636 ftrace_enabled = 0; 637 #endif 638 } 639 640 /* 641 * Ftrace disable/restore without lock. Some synchronization mechanism 642 * must be used to prevent ftrace_enabled to be changed between 643 * disable/restore. 644 */ 645 static inline int __ftrace_enabled_save(void) 646 { 647 #ifdef CONFIG_FUNCTION_TRACER 648 int saved_ftrace_enabled = ftrace_enabled; 649 ftrace_enabled = 0; 650 return saved_ftrace_enabled; 651 #else 652 return 0; 653 #endif 654 } 655 656 static inline void __ftrace_enabled_restore(int enabled) 657 { 658 #ifdef CONFIG_FUNCTION_TRACER 659 ftrace_enabled = enabled; 660 #endif 661 } 662 663 /* All archs should have this, but we define it for consistency */ 664 #ifndef ftrace_return_address0 665 # define ftrace_return_address0 __builtin_return_address(0) 666 #endif 667 668 /* Archs may use other ways for ADDR1 and beyond */ 669 #ifndef ftrace_return_address 670 # ifdef CONFIG_FRAME_POINTER 671 # define ftrace_return_address(n) __builtin_return_address(n) 672 # else 673 # define ftrace_return_address(n) 0UL 674 # endif 675 #endif 676 677 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 678 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 679 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 680 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 681 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 682 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 683 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 684 685 #ifdef CONFIG_IRQSOFF_TRACER 686 extern void time_hardirqs_on(unsigned long a0, unsigned long a1); 687 extern void time_hardirqs_off(unsigned long a0, unsigned long a1); 688 #else 689 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } 690 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } 691 #endif 692 693 #ifdef CONFIG_PREEMPT_TRACER 694 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 695 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 696 #else 697 /* 698 * Use defines instead of static inlines because some arches will make code out 699 * of the CALLER_ADDR, when we really want these to be a real nop. 700 */ 701 # define trace_preempt_on(a0, a1) do { } while (0) 702 # define trace_preempt_off(a0, a1) do { } while (0) 703 #endif 704 705 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 706 extern void ftrace_init(void); 707 #else 708 static inline void ftrace_init(void) { } 709 #endif 710 711 /* 712 * Structure that defines an entry function trace. 713 */ 714 struct ftrace_graph_ent { 715 unsigned long func; /* Current function */ 716 int depth; 717 }; 718 719 /* 720 * Structure that defines a return function trace. 721 */ 722 struct ftrace_graph_ret { 723 unsigned long func; /* Current function */ 724 unsigned long long calltime; 725 unsigned long long rettime; 726 /* Number of functions that overran the depth limit for current task */ 727 unsigned long overrun; 728 int depth; 729 }; 730 731 /* Type of the callback handlers for tracing function graph*/ 732 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 733 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 734 735 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 736 737 /* for init task */ 738 #define INIT_FTRACE_GRAPH .ret_stack = NULL, 739 740 /* 741 * Stack of return addresses for functions 742 * of a thread. 743 * Used in struct thread_info 744 */ 745 struct ftrace_ret_stack { 746 unsigned long ret; 747 unsigned long func; 748 unsigned long long calltime; 749 unsigned long long subtime; 750 unsigned long fp; 751 }; 752 753 /* 754 * Primary handler of a function return. 755 * It relays on ftrace_return_to_handler. 756 * Defined in entry_32/64.S 757 */ 758 extern void return_to_handler(void); 759 760 extern int 761 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 762 unsigned long frame_pointer); 763 764 /* 765 * Sometimes we don't want to trace a function with the function 766 * graph tracer but we want them to keep traced by the usual function 767 * tracer if the function graph tracer is not configured. 768 */ 769 #define __notrace_funcgraph notrace 770 771 /* 772 * We want to which function is an entrypoint of a hardirq. 773 * That will help us to put a signal on output. 774 */ 775 #define __irq_entry __attribute__((__section__(".irqentry.text"))) 776 777 /* Limits of hardirq entrypoints */ 778 extern char __irqentry_text_start[]; 779 extern char __irqentry_text_end[]; 780 781 #define FTRACE_NOTRACE_DEPTH 65536 782 #define FTRACE_RETFUNC_DEPTH 50 783 #define FTRACE_RETSTACK_ALLOC_SIZE 32 784 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 785 trace_func_graph_ent_t entryfunc); 786 787 extern bool ftrace_graph_is_dead(void); 788 extern void ftrace_graph_stop(void); 789 790 /* The current handlers in use */ 791 extern trace_func_graph_ret_t ftrace_graph_return; 792 extern trace_func_graph_ent_t ftrace_graph_entry; 793 794 extern void unregister_ftrace_graph(void); 795 796 extern void ftrace_graph_init_task(struct task_struct *t); 797 extern void ftrace_graph_exit_task(struct task_struct *t); 798 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 799 800 static inline int task_curr_ret_stack(struct task_struct *t) 801 { 802 return t->curr_ret_stack; 803 } 804 805 static inline void pause_graph_tracing(void) 806 { 807 atomic_inc(¤t->tracing_graph_pause); 808 } 809 810 static inline void unpause_graph_tracing(void) 811 { 812 atomic_dec(¤t->tracing_graph_pause); 813 } 814 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 815 816 #define __notrace_funcgraph 817 #define __irq_entry 818 #define INIT_FTRACE_GRAPH 819 820 static inline void ftrace_graph_init_task(struct task_struct *t) { } 821 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 822 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 823 824 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 825 trace_func_graph_ent_t entryfunc) 826 { 827 return -1; 828 } 829 static inline void unregister_ftrace_graph(void) { } 830 831 static inline int task_curr_ret_stack(struct task_struct *tsk) 832 { 833 return -1; 834 } 835 836 static inline void pause_graph_tracing(void) { } 837 static inline void unpause_graph_tracing(void) { } 838 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 839 840 #ifdef CONFIG_TRACING 841 842 /* flags for current->trace */ 843 enum { 844 TSK_TRACE_FL_TRACE_BIT = 0, 845 TSK_TRACE_FL_GRAPH_BIT = 1, 846 }; 847 enum { 848 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 849 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 850 }; 851 852 static inline void set_tsk_trace_trace(struct task_struct *tsk) 853 { 854 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 855 } 856 857 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 858 { 859 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 860 } 861 862 static inline int test_tsk_trace_trace(struct task_struct *tsk) 863 { 864 return tsk->trace & TSK_TRACE_FL_TRACE; 865 } 866 867 static inline void set_tsk_trace_graph(struct task_struct *tsk) 868 { 869 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 870 } 871 872 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 873 { 874 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 875 } 876 877 static inline int test_tsk_trace_graph(struct task_struct *tsk) 878 { 879 return tsk->trace & TSK_TRACE_FL_GRAPH; 880 } 881 882 enum ftrace_dump_mode; 883 884 extern enum ftrace_dump_mode ftrace_dump_on_oops; 885 extern int tracepoint_printk; 886 887 extern void disable_trace_on_warning(void); 888 extern int __disable_trace_on_warning; 889 890 #ifdef CONFIG_PREEMPT 891 #define INIT_TRACE_RECURSION .trace_recursion = 0, 892 #endif 893 894 #else /* CONFIG_TRACING */ 895 static inline void disable_trace_on_warning(void) { } 896 #endif /* CONFIG_TRACING */ 897 898 #ifndef INIT_TRACE_RECURSION 899 #define INIT_TRACE_RECURSION 900 #endif 901 902 #ifdef CONFIG_FTRACE_SYSCALLS 903 904 unsigned long arch_syscall_addr(int nr); 905 906 #endif /* CONFIG_FTRACE_SYSCALLS */ 907 908 #endif /* _LINUX_FTRACE_H */ 909