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 !defined(CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST) || \ 37 !ARCH_SUPPORTS_FTRACE_OPS 38 # define FTRACE_FORCE_LIST_FUNC 1 39 #else 40 # define FTRACE_FORCE_LIST_FUNC 0 41 #endif 42 43 44 struct module; 45 struct ftrace_hash; 46 47 #ifdef CONFIG_FUNCTION_TRACER 48 49 extern int ftrace_enabled; 50 extern int 51 ftrace_enable_sysctl(struct ctl_table *table, int write, 52 void __user *buffer, size_t *lenp, 53 loff_t *ppos); 54 55 struct ftrace_ops; 56 57 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 58 struct ftrace_ops *op, struct pt_regs *regs); 59 60 /* 61 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 62 * set in the flags member. 63 * 64 * ENABLED - set/unset when ftrace_ops is registered/unregistered 65 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 66 * allocated ftrace_ops which need special care 67 * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops 68 * could be controled by following calls: 69 * ftrace_function_local_enable 70 * ftrace_function_local_disable 71 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 72 * and passed to the callback. If this flag is set, but the 73 * architecture does not support passing regs 74 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 75 * ftrace_ops will fail to register, unless the next flag 76 * is set. 77 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 78 * handler can handle an arch that does not save regs 79 * (the handler tests if regs == NULL), then it can set 80 * this flag instead. It will not fail registering the ftrace_ops 81 * but, the regs field will be NULL if the arch does not support 82 * passing regs to the handler. 83 * Note, if this flag is set, the SAVE_REGS flag will automatically 84 * get set upon registering the ftrace_ops, if the arch supports it. 85 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure 86 * that the call back has its own recursion protection. If it does 87 * not set this, then the ftrace infrastructure will add recursion 88 * protection for the caller. 89 * STUB - The ftrace_ops is just a place holder. 90 * INITIALIZED - The ftrace_ops has already been initialized (first use time 91 * register_ftrace_function() is called, it will initialized the ops) 92 * DELETED - The ops are being deleted, do not let them be registered again. 93 */ 94 enum { 95 FTRACE_OPS_FL_ENABLED = 1 << 0, 96 FTRACE_OPS_FL_DYNAMIC = 1 << 1, 97 FTRACE_OPS_FL_CONTROL = 1 << 2, 98 FTRACE_OPS_FL_SAVE_REGS = 1 << 3, 99 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 4, 100 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 5, 101 FTRACE_OPS_FL_STUB = 1 << 6, 102 FTRACE_OPS_FL_INITIALIZED = 1 << 7, 103 FTRACE_OPS_FL_DELETED = 1 << 8, 104 }; 105 106 /* 107 * Note, ftrace_ops can be referenced outside of RCU protection. 108 * (Although, for perf, the control ops prevent that). If ftrace_ops is 109 * allocated and not part of kernel core data, the unregistering of it will 110 * perform a scheduling on all CPUs to make sure that there are no more users. 111 * Depending on the load of the system that may take a bit of time. 112 * 113 * Any private data added must also take care not to be freed and if private 114 * data is added to a ftrace_ops that is in core code, the user of the 115 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 116 */ 117 struct ftrace_ops { 118 ftrace_func_t func; 119 struct ftrace_ops *next; 120 unsigned long flags; 121 int __percpu *disabled; 122 void *private; 123 #ifdef CONFIG_DYNAMIC_FTRACE 124 struct ftrace_hash *notrace_hash; 125 struct ftrace_hash *filter_hash; 126 struct mutex regex_lock; 127 #endif 128 }; 129 130 extern int function_trace_stop; 131 132 /* 133 * Type of the current tracing. 134 */ 135 enum ftrace_tracing_type_t { 136 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 137 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 138 }; 139 140 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 141 extern enum ftrace_tracing_type_t ftrace_tracing_type; 142 143 /** 144 * ftrace_stop - stop function tracer. 145 * 146 * A quick way to stop the function tracer. Note this an on off switch, 147 * it is not something that is recursive like preempt_disable. 148 * This does not disable the calling of mcount, it only stops the 149 * calling of functions from mcount. 150 */ 151 static inline void ftrace_stop(void) 152 { 153 function_trace_stop = 1; 154 } 155 156 /** 157 * ftrace_start - start the function tracer. 158 * 159 * This function is the inverse of ftrace_stop. This does not enable 160 * the function tracing if the function tracer is disabled. This only 161 * sets the function tracer flag to continue calling the functions 162 * from mcount. 163 */ 164 static inline void ftrace_start(void) 165 { 166 function_trace_stop = 0; 167 } 168 169 /* 170 * The ftrace_ops must be a static and should also 171 * be read_mostly. These functions do modify read_mostly variables 172 * so use them sparely. Never free an ftrace_op or modify the 173 * next pointer after it has been registered. Even after unregistering 174 * it, the next pointer may still be used internally. 175 */ 176 int register_ftrace_function(struct ftrace_ops *ops); 177 int unregister_ftrace_function(struct ftrace_ops *ops); 178 void clear_ftrace_function(void); 179 180 /** 181 * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu 182 * 183 * This function enables tracing on current cpu by decreasing 184 * the per cpu control variable. 185 * It must be called with preemption disabled and only on ftrace_ops 186 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 187 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 188 */ 189 static inline void ftrace_function_local_enable(struct ftrace_ops *ops) 190 { 191 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 192 return; 193 194 (*this_cpu_ptr(ops->disabled))--; 195 } 196 197 /** 198 * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu 199 * 200 * This function enables tracing on current cpu by decreasing 201 * the per cpu control variable. 202 * It must be called with preemption disabled and only on ftrace_ops 203 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 204 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 205 */ 206 static inline void ftrace_function_local_disable(struct ftrace_ops *ops) 207 { 208 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 209 return; 210 211 (*this_cpu_ptr(ops->disabled))++; 212 } 213 214 /** 215 * ftrace_function_local_disabled - returns ftrace_ops disabled value 216 * on current cpu 217 * 218 * This function returns value of ftrace_ops::disabled on current cpu. 219 * It must be called with preemption disabled and only on ftrace_ops 220 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 221 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 222 */ 223 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) 224 { 225 WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)); 226 return *this_cpu_ptr(ops->disabled); 227 } 228 229 extern void ftrace_stub(unsigned long a0, unsigned long a1, 230 struct ftrace_ops *op, struct pt_regs *regs); 231 232 #else /* !CONFIG_FUNCTION_TRACER */ 233 /* 234 * (un)register_ftrace_function must be a macro since the ops parameter 235 * must not be evaluated. 236 */ 237 #define register_ftrace_function(ops) ({ 0; }) 238 #define unregister_ftrace_function(ops) ({ 0; }) 239 static inline int ftrace_nr_registered_ops(void) 240 { 241 return 0; 242 } 243 static inline void clear_ftrace_function(void) { } 244 static inline void ftrace_kill(void) { } 245 static inline void ftrace_stop(void) { } 246 static inline void ftrace_start(void) { } 247 #endif /* CONFIG_FUNCTION_TRACER */ 248 249 #ifdef CONFIG_STACK_TRACER 250 extern int stack_tracer_enabled; 251 int 252 stack_trace_sysctl(struct ctl_table *table, int write, 253 void __user *buffer, size_t *lenp, 254 loff_t *ppos); 255 #endif 256 257 struct ftrace_func_command { 258 struct list_head list; 259 char *name; 260 int (*func)(struct ftrace_hash *hash, 261 char *func, char *cmd, 262 char *params, int enable); 263 }; 264 265 #ifdef CONFIG_DYNAMIC_FTRACE 266 267 int ftrace_arch_code_modify_prepare(void); 268 int ftrace_arch_code_modify_post_process(void); 269 270 void ftrace_bug(int err, unsigned long ip); 271 272 struct seq_file; 273 274 struct ftrace_probe_ops { 275 void (*func)(unsigned long ip, 276 unsigned long parent_ip, 277 void **data); 278 int (*init)(struct ftrace_probe_ops *ops, 279 unsigned long ip, void **data); 280 void (*free)(struct ftrace_probe_ops *ops, 281 unsigned long ip, void **data); 282 int (*print)(struct seq_file *m, 283 unsigned long ip, 284 struct ftrace_probe_ops *ops, 285 void *data); 286 }; 287 288 extern int 289 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 290 void *data); 291 extern void 292 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 293 void *data); 294 extern void 295 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops); 296 extern void unregister_ftrace_function_probe_all(char *glob); 297 298 extern int ftrace_text_reserved(const void *start, const void *end); 299 300 extern int ftrace_nr_registered_ops(void); 301 302 /* 303 * The dyn_ftrace record's flags field is split into two parts. 304 * the first part which is '0-FTRACE_REF_MAX' is a counter of 305 * the number of callbacks that have registered the function that 306 * the dyn_ftrace descriptor represents. 307 * 308 * The second part is a mask: 309 * ENABLED - the function is being traced 310 * REGS - the record wants the function to save regs 311 * REGS_EN - the function is set up to save regs. 312 * 313 * When a new ftrace_ops is registered and wants a function to save 314 * pt_regs, the rec->flag REGS is set. When the function has been 315 * set up to save regs, the REG_EN flag is set. Once a function 316 * starts saving regs it will do so until all ftrace_ops are removed 317 * from tracing that function. 318 */ 319 enum { 320 FTRACE_FL_ENABLED = (1UL << 29), 321 FTRACE_FL_REGS = (1UL << 30), 322 FTRACE_FL_REGS_EN = (1UL << 31) 323 }; 324 325 #define FTRACE_FL_MASK (0x7UL << 29) 326 #define FTRACE_REF_MAX ((1UL << 29) - 1) 327 328 struct dyn_ftrace { 329 unsigned long ip; /* address of mcount call-site */ 330 unsigned long flags; 331 struct dyn_arch_ftrace arch; 332 }; 333 334 int ftrace_force_update(void); 335 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 336 int remove, int reset); 337 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 338 int len, int reset); 339 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 340 int len, int reset); 341 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 342 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 343 void ftrace_free_filter(struct ftrace_ops *ops); 344 345 int register_ftrace_command(struct ftrace_func_command *cmd); 346 int unregister_ftrace_command(struct ftrace_func_command *cmd); 347 348 enum { 349 FTRACE_UPDATE_CALLS = (1 << 0), 350 FTRACE_DISABLE_CALLS = (1 << 1), 351 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 352 FTRACE_START_FUNC_RET = (1 << 3), 353 FTRACE_STOP_FUNC_RET = (1 << 4), 354 }; 355 356 /* 357 * The FTRACE_UPDATE_* enum is used to pass information back 358 * from the ftrace_update_record() and ftrace_test_record() 359 * functions. These are called by the code update routines 360 * to find out what is to be done for a given function. 361 * 362 * IGNORE - The function is already what we want it to be 363 * MAKE_CALL - Start tracing the function 364 * MODIFY_CALL - Stop saving regs for the function 365 * MAKE_NOP - Stop tracing the function 366 */ 367 enum { 368 FTRACE_UPDATE_IGNORE, 369 FTRACE_UPDATE_MAKE_CALL, 370 FTRACE_UPDATE_MODIFY_CALL, 371 FTRACE_UPDATE_MAKE_NOP, 372 }; 373 374 enum { 375 FTRACE_ITER_FILTER = (1 << 0), 376 FTRACE_ITER_NOTRACE = (1 << 1), 377 FTRACE_ITER_PRINTALL = (1 << 2), 378 FTRACE_ITER_DO_HASH = (1 << 3), 379 FTRACE_ITER_HASH = (1 << 4), 380 FTRACE_ITER_ENABLED = (1 << 5), 381 }; 382 383 void arch_ftrace_update_code(int command); 384 385 struct ftrace_rec_iter; 386 387 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 388 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 389 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 390 391 #define for_ftrace_rec_iter(iter) \ 392 for (iter = ftrace_rec_iter_start(); \ 393 iter; \ 394 iter = ftrace_rec_iter_next(iter)) 395 396 397 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 398 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 399 void ftrace_run_stop_machine(int command); 400 unsigned long ftrace_location(unsigned long ip); 401 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 402 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 403 404 extern ftrace_func_t ftrace_trace_function; 405 406 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 407 struct inode *inode, struct file *file); 408 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 409 size_t cnt, loff_t *ppos); 410 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 411 size_t cnt, loff_t *ppos); 412 int ftrace_regex_release(struct inode *inode, struct file *file); 413 414 void __init 415 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 416 417 /* defined in arch */ 418 extern int ftrace_ip_converted(unsigned long ip); 419 extern int ftrace_dyn_arch_init(void); 420 extern void ftrace_replace_code(int enable); 421 extern int ftrace_update_ftrace_func(ftrace_func_t func); 422 extern void ftrace_caller(void); 423 extern void ftrace_regs_caller(void); 424 extern void ftrace_call(void); 425 extern void ftrace_regs_call(void); 426 extern void mcount_call(void); 427 428 void ftrace_modify_all_code(int command); 429 430 #ifndef FTRACE_ADDR 431 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 432 #endif 433 434 #ifndef FTRACE_REGS_ADDR 435 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 436 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 437 #else 438 # define FTRACE_REGS_ADDR FTRACE_ADDR 439 #endif 440 #endif 441 442 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 443 extern void ftrace_graph_caller(void); 444 extern int ftrace_enable_ftrace_graph_caller(void); 445 extern int ftrace_disable_ftrace_graph_caller(void); 446 #else 447 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 448 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 449 #endif 450 451 /** 452 * ftrace_make_nop - convert code into nop 453 * @mod: module structure if called by module load initialization 454 * @rec: the mcount call site record 455 * @addr: the address that the call site should be calling 456 * 457 * This is a very sensitive operation and great care needs 458 * to be taken by the arch. The operation should carefully 459 * read the location, check to see if what is read is indeed 460 * what we expect it to be, and then on success of the compare, 461 * it should write to the location. 462 * 463 * The code segment at @rec->ip should be a caller to @addr 464 * 465 * Return must be: 466 * 0 on success 467 * -EFAULT on error reading the location 468 * -EINVAL on a failed compare of the contents 469 * -EPERM on error writing to the location 470 * Any other value will be considered a failure. 471 */ 472 extern int ftrace_make_nop(struct module *mod, 473 struct dyn_ftrace *rec, unsigned long addr); 474 475 /** 476 * ftrace_make_call - convert a nop call site into a call to addr 477 * @rec: the mcount call site record 478 * @addr: the address that the call site should call 479 * 480 * This is a very sensitive operation and great care needs 481 * to be taken by the arch. The operation should carefully 482 * read the location, check to see if what is read is indeed 483 * what we expect it to be, and then on success of the compare, 484 * it should write to the location. 485 * 486 * The code segment at @rec->ip should be a nop 487 * 488 * Return must be: 489 * 0 on success 490 * -EFAULT on error reading the location 491 * -EINVAL on a failed compare of the contents 492 * -EPERM on error writing to the location 493 * Any other value will be considered a failure. 494 */ 495 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 496 497 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 498 /** 499 * ftrace_modify_call - convert from one addr to another (no nop) 500 * @rec: the mcount call site record 501 * @old_addr: the address expected to be currently called to 502 * @addr: the address to change to 503 * 504 * This is a very sensitive operation and great care needs 505 * to be taken by the arch. The operation should carefully 506 * read the location, check to see if what is read is indeed 507 * what we expect it to be, and then on success of the compare, 508 * it should write to the location. 509 * 510 * The code segment at @rec->ip should be a caller to @old_addr 511 * 512 * Return must be: 513 * 0 on success 514 * -EFAULT on error reading the location 515 * -EINVAL on a failed compare of the contents 516 * -EPERM on error writing to the location 517 * Any other value will be considered a failure. 518 */ 519 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 520 unsigned long addr); 521 #else 522 /* Should never be called */ 523 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 524 unsigned long addr) 525 { 526 return -EINVAL; 527 } 528 #endif 529 530 /* May be defined in arch */ 531 extern int ftrace_arch_read_dyn_info(char *buf, int size); 532 533 extern int skip_trace(unsigned long ip); 534 extern void ftrace_module_init(struct module *mod); 535 536 extern void ftrace_disable_daemon(void); 537 extern void ftrace_enable_daemon(void); 538 #else /* CONFIG_DYNAMIC_FTRACE */ 539 static inline int skip_trace(unsigned long ip) { return 0; } 540 static inline int ftrace_force_update(void) { return 0; } 541 static inline void ftrace_disable_daemon(void) { } 542 static inline void ftrace_enable_daemon(void) { } 543 static inline void ftrace_release_mod(struct module *mod) {} 544 static inline void ftrace_module_init(struct module *mod) {} 545 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd) 546 { 547 return -EINVAL; 548 } 549 static inline __init int unregister_ftrace_command(char *cmd_name) 550 { 551 return -EINVAL; 552 } 553 static inline int ftrace_text_reserved(const void *start, const void *end) 554 { 555 return 0; 556 } 557 static inline unsigned long ftrace_location(unsigned long ip) 558 { 559 return 0; 560 } 561 562 /* 563 * Again users of functions that have ftrace_ops may not 564 * have them defined when ftrace is not enabled, but these 565 * functions may still be called. Use a macro instead of inline. 566 */ 567 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 568 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 569 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 570 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 571 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 572 #define ftrace_free_filter(ops) do { } while (0) 573 574 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 575 size_t cnt, loff_t *ppos) { return -ENODEV; } 576 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 577 size_t cnt, loff_t *ppos) { return -ENODEV; } 578 static inline int 579 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 580 #endif /* CONFIG_DYNAMIC_FTRACE */ 581 582 /* totally disable ftrace - can not re-enable after this */ 583 void ftrace_kill(void); 584 585 static inline void tracer_disable(void) 586 { 587 #ifdef CONFIG_FUNCTION_TRACER 588 ftrace_enabled = 0; 589 #endif 590 } 591 592 /* 593 * Ftrace disable/restore without lock. Some synchronization mechanism 594 * must be used to prevent ftrace_enabled to be changed between 595 * disable/restore. 596 */ 597 static inline int __ftrace_enabled_save(void) 598 { 599 #ifdef CONFIG_FUNCTION_TRACER 600 int saved_ftrace_enabled = ftrace_enabled; 601 ftrace_enabled = 0; 602 return saved_ftrace_enabled; 603 #else 604 return 0; 605 #endif 606 } 607 608 static inline void __ftrace_enabled_restore(int enabled) 609 { 610 #ifdef CONFIG_FUNCTION_TRACER 611 ftrace_enabled = enabled; 612 #endif 613 } 614 615 /* All archs should have this, but we define it for consistency */ 616 #ifndef ftrace_return_address0 617 # define ftrace_return_address0 __builtin_return_address(0) 618 #endif 619 620 /* Archs may use other ways for ADDR1 and beyond */ 621 #ifndef ftrace_return_address 622 # ifdef CONFIG_FRAME_POINTER 623 # define ftrace_return_address(n) __builtin_return_address(n) 624 # else 625 # define ftrace_return_address(n) 0UL 626 # endif 627 #endif 628 629 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 630 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 631 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 632 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 633 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 634 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 635 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 636 637 #ifdef CONFIG_IRQSOFF_TRACER 638 extern void time_hardirqs_on(unsigned long a0, unsigned long a1); 639 extern void time_hardirqs_off(unsigned long a0, unsigned long a1); 640 #else 641 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } 642 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } 643 #endif 644 645 #ifdef CONFIG_PREEMPT_TRACER 646 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 647 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 648 #else 649 /* 650 * Use defines instead of static inlines because some arches will make code out 651 * of the CALLER_ADDR, when we really want these to be a real nop. 652 */ 653 # define trace_preempt_on(a0, a1) do { } while (0) 654 # define trace_preempt_off(a0, a1) do { } while (0) 655 #endif 656 657 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 658 extern void ftrace_init(void); 659 #else 660 static inline void ftrace_init(void) { } 661 #endif 662 663 /* 664 * Structure that defines an entry function trace. 665 */ 666 struct ftrace_graph_ent { 667 unsigned long func; /* Current function */ 668 int depth; 669 }; 670 671 /* 672 * Structure that defines a return function trace. 673 */ 674 struct ftrace_graph_ret { 675 unsigned long func; /* Current function */ 676 unsigned long long calltime; 677 unsigned long long rettime; 678 /* Number of functions that overran the depth limit for current task */ 679 unsigned long overrun; 680 int depth; 681 }; 682 683 /* Type of the callback handlers for tracing function graph*/ 684 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 685 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 686 687 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 688 689 /* for init task */ 690 #define INIT_FTRACE_GRAPH .ret_stack = NULL, 691 692 /* 693 * Stack of return addresses for functions 694 * of a thread. 695 * Used in struct thread_info 696 */ 697 struct ftrace_ret_stack { 698 unsigned long ret; 699 unsigned long func; 700 unsigned long long calltime; 701 unsigned long long subtime; 702 unsigned long fp; 703 }; 704 705 /* 706 * Primary handler of a function return. 707 * It relays on ftrace_return_to_handler. 708 * Defined in entry_32/64.S 709 */ 710 extern void return_to_handler(void); 711 712 extern int 713 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 714 unsigned long frame_pointer); 715 716 /* 717 * Sometimes we don't want to trace a function with the function 718 * graph tracer but we want them to keep traced by the usual function 719 * tracer if the function graph tracer is not configured. 720 */ 721 #define __notrace_funcgraph notrace 722 723 /* 724 * We want to which function is an entrypoint of a hardirq. 725 * That will help us to put a signal on output. 726 */ 727 #define __irq_entry __attribute__((__section__(".irqentry.text"))) 728 729 /* Limits of hardirq entrypoints */ 730 extern char __irqentry_text_start[]; 731 extern char __irqentry_text_end[]; 732 733 #define FTRACE_NOTRACE_DEPTH 65536 734 #define FTRACE_RETFUNC_DEPTH 50 735 #define FTRACE_RETSTACK_ALLOC_SIZE 32 736 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 737 trace_func_graph_ent_t entryfunc); 738 739 extern void ftrace_graph_stop(void); 740 741 /* The current handlers in use */ 742 extern trace_func_graph_ret_t ftrace_graph_return; 743 extern trace_func_graph_ent_t ftrace_graph_entry; 744 745 extern void unregister_ftrace_graph(void); 746 747 extern void ftrace_graph_init_task(struct task_struct *t); 748 extern void ftrace_graph_exit_task(struct task_struct *t); 749 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 750 751 static inline int task_curr_ret_stack(struct task_struct *t) 752 { 753 return t->curr_ret_stack; 754 } 755 756 static inline void pause_graph_tracing(void) 757 { 758 atomic_inc(¤t->tracing_graph_pause); 759 } 760 761 static inline void unpause_graph_tracing(void) 762 { 763 atomic_dec(¤t->tracing_graph_pause); 764 } 765 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 766 767 #define __notrace_funcgraph 768 #define __irq_entry 769 #define INIT_FTRACE_GRAPH 770 771 static inline void ftrace_graph_init_task(struct task_struct *t) { } 772 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 773 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 774 775 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 776 trace_func_graph_ent_t entryfunc) 777 { 778 return -1; 779 } 780 static inline void unregister_ftrace_graph(void) { } 781 782 static inline int task_curr_ret_stack(struct task_struct *tsk) 783 { 784 return -1; 785 } 786 787 static inline void pause_graph_tracing(void) { } 788 static inline void unpause_graph_tracing(void) { } 789 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 790 791 #ifdef CONFIG_TRACING 792 793 /* flags for current->trace */ 794 enum { 795 TSK_TRACE_FL_TRACE_BIT = 0, 796 TSK_TRACE_FL_GRAPH_BIT = 1, 797 }; 798 enum { 799 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 800 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 801 }; 802 803 static inline void set_tsk_trace_trace(struct task_struct *tsk) 804 { 805 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 806 } 807 808 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 809 { 810 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 811 } 812 813 static inline int test_tsk_trace_trace(struct task_struct *tsk) 814 { 815 return tsk->trace & TSK_TRACE_FL_TRACE; 816 } 817 818 static inline void set_tsk_trace_graph(struct task_struct *tsk) 819 { 820 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 821 } 822 823 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 824 { 825 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 826 } 827 828 static inline int test_tsk_trace_graph(struct task_struct *tsk) 829 { 830 return tsk->trace & TSK_TRACE_FL_GRAPH; 831 } 832 833 enum ftrace_dump_mode; 834 835 extern enum ftrace_dump_mode ftrace_dump_on_oops; 836 837 extern void disable_trace_on_warning(void); 838 extern int __disable_trace_on_warning; 839 840 #ifdef CONFIG_PREEMPT 841 #define INIT_TRACE_RECURSION .trace_recursion = 0, 842 #endif 843 844 #else /* CONFIG_TRACING */ 845 static inline void disable_trace_on_warning(void) { } 846 #endif /* CONFIG_TRACING */ 847 848 #ifndef INIT_TRACE_RECURSION 849 #define INIT_TRACE_RECURSION 850 #endif 851 852 #ifdef CONFIG_FTRACE_SYSCALLS 853 854 unsigned long arch_syscall_addr(int nr); 855 856 #endif /* CONFIG_FTRACE_SYSCALLS */ 857 858 #endif /* _LINUX_FTRACE_H */ 859