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 43 struct module; 44 struct ftrace_hash; 45 46 #ifdef CONFIG_FUNCTION_TRACER 47 48 extern int ftrace_enabled; 49 extern int 50 ftrace_enable_sysctl(struct ctl_table *table, int write, 51 void __user *buffer, size_t *lenp, 52 loff_t *ppos); 53 54 struct ftrace_ops; 55 56 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 57 struct ftrace_ops *op, struct pt_regs *regs); 58 59 /* 60 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 61 * set in the flags member. 62 * 63 * ENABLED - set/unset when ftrace_ops is registered/unregistered 64 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 65 * allocated ftrace_ops which need special care 66 * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops 67 * could be controled by following calls: 68 * ftrace_function_local_enable 69 * ftrace_function_local_disable 70 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 71 * and passed to the callback. If this flag is set, but the 72 * architecture does not support passing regs 73 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 74 * ftrace_ops will fail to register, unless the next flag 75 * is set. 76 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 77 * handler can handle an arch that does not save regs 78 * (the handler tests if regs == NULL), then it can set 79 * this flag instead. It will not fail registering the ftrace_ops 80 * but, the regs field will be NULL if the arch does not support 81 * passing regs to the handler. 82 * Note, if this flag is set, the SAVE_REGS flag will automatically 83 * get set upon registering the ftrace_ops, if the arch supports it. 84 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure 85 * that the call back has its own recursion protection. If it does 86 * not set this, then the ftrace infrastructure will add recursion 87 * protection for the caller. 88 * STUB - The ftrace_ops is just a place holder. 89 * INITIALIZED - The ftrace_ops has already been initialized (first use time 90 * register_ftrace_function() is called, it will initialized the ops) 91 * DELETED - The ops are being deleted, do not let them be registered again. 92 */ 93 enum { 94 FTRACE_OPS_FL_ENABLED = 1 << 0, 95 FTRACE_OPS_FL_DYNAMIC = 1 << 1, 96 FTRACE_OPS_FL_CONTROL = 1 << 2, 97 FTRACE_OPS_FL_SAVE_REGS = 1 << 3, 98 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 4, 99 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 5, 100 FTRACE_OPS_FL_STUB = 1 << 6, 101 FTRACE_OPS_FL_INITIALIZED = 1 << 7, 102 FTRACE_OPS_FL_DELETED = 1 << 8, 103 }; 104 105 /* 106 * Note, ftrace_ops can be referenced outside of RCU protection. 107 * (Although, for perf, the control ops prevent that). If ftrace_ops is 108 * allocated and not part of kernel core data, the unregistering of it will 109 * perform a scheduling on all CPUs to make sure that there are no more users. 110 * Depending on the load of the system that may take a bit of time. 111 * 112 * Any private data added must also take care not to be freed and if private 113 * data is added to a ftrace_ops that is in core code, the user of the 114 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 115 */ 116 struct ftrace_ops { 117 ftrace_func_t func; 118 struct ftrace_ops *next; 119 unsigned long flags; 120 void *private; 121 int __percpu *disabled; 122 #ifdef CONFIG_DYNAMIC_FTRACE 123 int nr_trampolines; 124 struct ftrace_hash *notrace_hash; 125 struct ftrace_hash *filter_hash; 126 struct ftrace_hash *tramp_hash; 127 struct mutex regex_lock; 128 unsigned long trampoline; 129 #endif 130 }; 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 * The ftrace_ops must be a static and should also 145 * be read_mostly. These functions do modify read_mostly variables 146 * so use them sparely. Never free an ftrace_op or modify the 147 * next pointer after it has been registered. Even after unregistering 148 * it, the next pointer may still be used internally. 149 */ 150 int register_ftrace_function(struct ftrace_ops *ops); 151 int unregister_ftrace_function(struct ftrace_ops *ops); 152 void clear_ftrace_function(void); 153 154 /** 155 * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu 156 * 157 * This function enables tracing on current cpu by decreasing 158 * the per cpu control variable. 159 * It must be called with preemption disabled and only on ftrace_ops 160 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 161 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 162 */ 163 static inline void ftrace_function_local_enable(struct ftrace_ops *ops) 164 { 165 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 166 return; 167 168 (*this_cpu_ptr(ops->disabled))--; 169 } 170 171 /** 172 * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu 173 * 174 * This function enables tracing on current cpu by decreasing 175 * the per cpu control variable. 176 * It must be called with preemption disabled and only on ftrace_ops 177 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 178 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 179 */ 180 static inline void ftrace_function_local_disable(struct ftrace_ops *ops) 181 { 182 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 183 return; 184 185 (*this_cpu_ptr(ops->disabled))++; 186 } 187 188 /** 189 * ftrace_function_local_disabled - returns ftrace_ops disabled value 190 * on current cpu 191 * 192 * This function returns value of ftrace_ops::disabled on current cpu. 193 * It must be called with preemption disabled and only on ftrace_ops 194 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 195 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 196 */ 197 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) 198 { 199 WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)); 200 return *this_cpu_ptr(ops->disabled); 201 } 202 203 extern void ftrace_stub(unsigned long a0, unsigned long a1, 204 struct ftrace_ops *op, struct pt_regs *regs); 205 206 #else /* !CONFIG_FUNCTION_TRACER */ 207 /* 208 * (un)register_ftrace_function must be a macro since the ops parameter 209 * must not be evaluated. 210 */ 211 #define register_ftrace_function(ops) ({ 0; }) 212 #define unregister_ftrace_function(ops) ({ 0; }) 213 static inline int ftrace_nr_registered_ops(void) 214 { 215 return 0; 216 } 217 static inline void clear_ftrace_function(void) { } 218 static inline void ftrace_kill(void) { } 219 #endif /* CONFIG_FUNCTION_TRACER */ 220 221 #ifdef CONFIG_STACK_TRACER 222 extern int stack_tracer_enabled; 223 int 224 stack_trace_sysctl(struct ctl_table *table, int write, 225 void __user *buffer, size_t *lenp, 226 loff_t *ppos); 227 #endif 228 229 struct ftrace_func_command { 230 struct list_head list; 231 char *name; 232 int (*func)(struct ftrace_hash *hash, 233 char *func, char *cmd, 234 char *params, int enable); 235 }; 236 237 #ifdef CONFIG_DYNAMIC_FTRACE 238 239 int ftrace_arch_code_modify_prepare(void); 240 int ftrace_arch_code_modify_post_process(void); 241 242 void ftrace_bug(int err, unsigned long ip); 243 244 struct seq_file; 245 246 struct ftrace_probe_ops { 247 void (*func)(unsigned long ip, 248 unsigned long parent_ip, 249 void **data); 250 int (*init)(struct ftrace_probe_ops *ops, 251 unsigned long ip, void **data); 252 void (*free)(struct ftrace_probe_ops *ops, 253 unsigned long ip, void **data); 254 int (*print)(struct seq_file *m, 255 unsigned long ip, 256 struct ftrace_probe_ops *ops, 257 void *data); 258 }; 259 260 extern int 261 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 262 void *data); 263 extern void 264 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 265 void *data); 266 extern void 267 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops); 268 extern void unregister_ftrace_function_probe_all(char *glob); 269 270 extern int ftrace_text_reserved(const void *start, const void *end); 271 272 extern int ftrace_nr_registered_ops(void); 273 274 /* 275 * The dyn_ftrace record's flags field is split into two parts. 276 * the first part which is '0-FTRACE_REF_MAX' is a counter of 277 * the number of callbacks that have registered the function that 278 * the dyn_ftrace descriptor represents. 279 * 280 * The second part is a mask: 281 * ENABLED - the function is being traced 282 * REGS - the record wants the function to save regs 283 * REGS_EN - the function is set up to save regs. 284 * 285 * When a new ftrace_ops is registered and wants a function to save 286 * pt_regs, the rec->flag REGS is set. When the function has been 287 * set up to save regs, the REG_EN flag is set. Once a function 288 * starts saving regs it will do so until all ftrace_ops are removed 289 * from tracing that function. 290 */ 291 enum { 292 FTRACE_FL_ENABLED = (1UL << 31), 293 FTRACE_FL_REGS = (1UL << 30), 294 FTRACE_FL_REGS_EN = (1UL << 29), 295 FTRACE_FL_TRAMP = (1UL << 28), 296 FTRACE_FL_TRAMP_EN = (1UL << 27), 297 }; 298 299 #define FTRACE_REF_MAX_SHIFT 27 300 #define FTRACE_FL_BITS 5 301 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 302 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 303 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 304 305 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 306 307 struct dyn_ftrace { 308 unsigned long ip; /* address of mcount call-site */ 309 unsigned long flags; 310 struct dyn_arch_ftrace arch; 311 }; 312 313 int ftrace_force_update(void); 314 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 315 int remove, int reset); 316 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 317 int len, int reset); 318 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 319 int len, int reset); 320 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 321 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 322 void ftrace_free_filter(struct ftrace_ops *ops); 323 324 int register_ftrace_command(struct ftrace_func_command *cmd); 325 int unregister_ftrace_command(struct ftrace_func_command *cmd); 326 327 enum { 328 FTRACE_UPDATE_CALLS = (1 << 0), 329 FTRACE_DISABLE_CALLS = (1 << 1), 330 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 331 FTRACE_START_FUNC_RET = (1 << 3), 332 FTRACE_STOP_FUNC_RET = (1 << 4), 333 }; 334 335 /* 336 * The FTRACE_UPDATE_* enum is used to pass information back 337 * from the ftrace_update_record() and ftrace_test_record() 338 * functions. These are called by the code update routines 339 * to find out what is to be done for a given function. 340 * 341 * IGNORE - The function is already what we want it to be 342 * MAKE_CALL - Start tracing the function 343 * MODIFY_CALL - Stop saving regs for the function 344 * MAKE_NOP - Stop tracing the function 345 */ 346 enum { 347 FTRACE_UPDATE_IGNORE, 348 FTRACE_UPDATE_MAKE_CALL, 349 FTRACE_UPDATE_MODIFY_CALL, 350 FTRACE_UPDATE_MAKE_NOP, 351 }; 352 353 enum { 354 FTRACE_ITER_FILTER = (1 << 0), 355 FTRACE_ITER_NOTRACE = (1 << 1), 356 FTRACE_ITER_PRINTALL = (1 << 2), 357 FTRACE_ITER_DO_HASH = (1 << 3), 358 FTRACE_ITER_HASH = (1 << 4), 359 FTRACE_ITER_ENABLED = (1 << 5), 360 }; 361 362 void arch_ftrace_update_code(int command); 363 364 struct ftrace_rec_iter; 365 366 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 367 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 368 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 369 370 #define for_ftrace_rec_iter(iter) \ 371 for (iter = ftrace_rec_iter_start(); \ 372 iter; \ 373 iter = ftrace_rec_iter_next(iter)) 374 375 376 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 377 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 378 void ftrace_run_stop_machine(int command); 379 unsigned long ftrace_location(unsigned long ip); 380 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 381 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 382 383 extern ftrace_func_t ftrace_trace_function; 384 385 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 386 struct inode *inode, struct file *file); 387 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 388 size_t cnt, loff_t *ppos); 389 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 390 size_t cnt, loff_t *ppos); 391 int ftrace_regex_release(struct inode *inode, struct file *file); 392 393 void __init 394 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 395 396 /* defined in arch */ 397 extern int ftrace_ip_converted(unsigned long ip); 398 extern int ftrace_dyn_arch_init(void); 399 extern void ftrace_replace_code(int enable); 400 extern int ftrace_update_ftrace_func(ftrace_func_t func); 401 extern void ftrace_caller(void); 402 extern void ftrace_regs_caller(void); 403 extern void ftrace_call(void); 404 extern void ftrace_regs_call(void); 405 extern void mcount_call(void); 406 407 void ftrace_modify_all_code(int command); 408 409 #ifndef FTRACE_ADDR 410 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 411 #endif 412 413 #ifndef FTRACE_GRAPH_ADDR 414 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 415 #endif 416 417 #ifndef FTRACE_REGS_ADDR 418 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 419 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 420 #else 421 # define FTRACE_REGS_ADDR FTRACE_ADDR 422 #endif 423 #endif 424 425 /* 426 * If an arch would like functions that are only traced 427 * by the function graph tracer to jump directly to its own 428 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 429 * to be that address to jump to. 430 */ 431 #ifndef FTRACE_GRAPH_TRAMP_ADDR 432 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 433 #endif 434 435 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 436 extern void ftrace_graph_caller(void); 437 extern int ftrace_enable_ftrace_graph_caller(void); 438 extern int ftrace_disable_ftrace_graph_caller(void); 439 #else 440 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 441 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 442 #endif 443 444 /** 445 * ftrace_make_nop - convert code into nop 446 * @mod: module structure if called by module load initialization 447 * @rec: the mcount call site record 448 * @addr: the address that the call site should be calling 449 * 450 * This is a very sensitive operation and great care needs 451 * to be taken by the arch. The operation should carefully 452 * read the location, check to see if what is read is indeed 453 * what we expect it to be, and then on success of the compare, 454 * it should write to the location. 455 * 456 * The code segment at @rec->ip should be a caller to @addr 457 * 458 * Return must be: 459 * 0 on success 460 * -EFAULT on error reading the location 461 * -EINVAL on a failed compare of the contents 462 * -EPERM on error writing to the location 463 * Any other value will be considered a failure. 464 */ 465 extern int ftrace_make_nop(struct module *mod, 466 struct dyn_ftrace *rec, unsigned long addr); 467 468 /** 469 * ftrace_make_call - convert a nop call site into a call to addr 470 * @rec: the mcount call site record 471 * @addr: the address that the call site should call 472 * 473 * This is a very sensitive operation and great care needs 474 * to be taken by the arch. The operation should carefully 475 * read the location, check to see if what is read is indeed 476 * what we expect it to be, and then on success of the compare, 477 * it should write to the location. 478 * 479 * The code segment at @rec->ip should be a nop 480 * 481 * Return must be: 482 * 0 on success 483 * -EFAULT on error reading the location 484 * -EINVAL on a failed compare of the contents 485 * -EPERM on error writing to the location 486 * Any other value will be considered a failure. 487 */ 488 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 489 490 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 491 /** 492 * ftrace_modify_call - convert from one addr to another (no nop) 493 * @rec: the mcount call site record 494 * @old_addr: the address expected to be currently called to 495 * @addr: the address to change to 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 @old_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_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 513 unsigned long addr); 514 #else 515 /* Should never be called */ 516 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 517 unsigned long addr) 518 { 519 return -EINVAL; 520 } 521 #endif 522 523 /* May be defined in arch */ 524 extern int ftrace_arch_read_dyn_info(char *buf, int size); 525 526 extern int skip_trace(unsigned long ip); 527 extern void ftrace_module_init(struct module *mod); 528 529 extern void ftrace_disable_daemon(void); 530 extern void ftrace_enable_daemon(void); 531 #else /* CONFIG_DYNAMIC_FTRACE */ 532 static inline int skip_trace(unsigned long ip) { return 0; } 533 static inline int ftrace_force_update(void) { return 0; } 534 static inline void ftrace_disable_daemon(void) { } 535 static inline void ftrace_enable_daemon(void) { } 536 static inline void ftrace_release_mod(struct module *mod) {} 537 static inline void ftrace_module_init(struct module *mod) {} 538 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd) 539 { 540 return -EINVAL; 541 } 542 static inline __init int unregister_ftrace_command(char *cmd_name) 543 { 544 return -EINVAL; 545 } 546 static inline int ftrace_text_reserved(const void *start, const void *end) 547 { 548 return 0; 549 } 550 static inline unsigned long ftrace_location(unsigned long ip) 551 { 552 return 0; 553 } 554 555 /* 556 * Again users of functions that have ftrace_ops may not 557 * have them defined when ftrace is not enabled, but these 558 * functions may still be called. Use a macro instead of inline. 559 */ 560 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 561 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 562 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 563 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 564 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 565 #define ftrace_free_filter(ops) do { } while (0) 566 567 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 568 size_t cnt, loff_t *ppos) { return -ENODEV; } 569 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 570 size_t cnt, loff_t *ppos) { return -ENODEV; } 571 static inline int 572 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 573 #endif /* CONFIG_DYNAMIC_FTRACE */ 574 575 /* totally disable ftrace - can not re-enable after this */ 576 void ftrace_kill(void); 577 578 static inline void tracer_disable(void) 579 { 580 #ifdef CONFIG_FUNCTION_TRACER 581 ftrace_enabled = 0; 582 #endif 583 } 584 585 /* 586 * Ftrace disable/restore without lock. Some synchronization mechanism 587 * must be used to prevent ftrace_enabled to be changed between 588 * disable/restore. 589 */ 590 static inline int __ftrace_enabled_save(void) 591 { 592 #ifdef CONFIG_FUNCTION_TRACER 593 int saved_ftrace_enabled = ftrace_enabled; 594 ftrace_enabled = 0; 595 return saved_ftrace_enabled; 596 #else 597 return 0; 598 #endif 599 } 600 601 static inline void __ftrace_enabled_restore(int enabled) 602 { 603 #ifdef CONFIG_FUNCTION_TRACER 604 ftrace_enabled = enabled; 605 #endif 606 } 607 608 /* All archs should have this, but we define it for consistency */ 609 #ifndef ftrace_return_address0 610 # define ftrace_return_address0 __builtin_return_address(0) 611 #endif 612 613 /* Archs may use other ways for ADDR1 and beyond */ 614 #ifndef ftrace_return_address 615 # ifdef CONFIG_FRAME_POINTER 616 # define ftrace_return_address(n) __builtin_return_address(n) 617 # else 618 # define ftrace_return_address(n) 0UL 619 # endif 620 #endif 621 622 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 623 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 624 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 625 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 626 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 627 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 628 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 629 630 #ifdef CONFIG_IRQSOFF_TRACER 631 extern void time_hardirqs_on(unsigned long a0, unsigned long a1); 632 extern void time_hardirqs_off(unsigned long a0, unsigned long a1); 633 #else 634 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } 635 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } 636 #endif 637 638 #ifdef CONFIG_PREEMPT_TRACER 639 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 640 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 641 #else 642 /* 643 * Use defines instead of static inlines because some arches will make code out 644 * of the CALLER_ADDR, when we really want these to be a real nop. 645 */ 646 # define trace_preempt_on(a0, a1) do { } while (0) 647 # define trace_preempt_off(a0, a1) do { } while (0) 648 #endif 649 650 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 651 extern void ftrace_init(void); 652 #else 653 static inline void ftrace_init(void) { } 654 #endif 655 656 /* 657 * Structure that defines an entry function trace. 658 */ 659 struct ftrace_graph_ent { 660 unsigned long func; /* Current function */ 661 int depth; 662 }; 663 664 /* 665 * Structure that defines a return function trace. 666 */ 667 struct ftrace_graph_ret { 668 unsigned long func; /* Current function */ 669 unsigned long long calltime; 670 unsigned long long rettime; 671 /* Number of functions that overran the depth limit for current task */ 672 unsigned long overrun; 673 int depth; 674 }; 675 676 /* Type of the callback handlers for tracing function graph*/ 677 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 678 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 679 680 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 681 682 /* for init task */ 683 #define INIT_FTRACE_GRAPH .ret_stack = NULL, 684 685 /* 686 * Stack of return addresses for functions 687 * of a thread. 688 * Used in struct thread_info 689 */ 690 struct ftrace_ret_stack { 691 unsigned long ret; 692 unsigned long func; 693 unsigned long long calltime; 694 unsigned long long subtime; 695 unsigned long fp; 696 }; 697 698 /* 699 * Primary handler of a function return. 700 * It relays on ftrace_return_to_handler. 701 * Defined in entry_32/64.S 702 */ 703 extern void return_to_handler(void); 704 705 extern int 706 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 707 unsigned long frame_pointer); 708 709 /* 710 * Sometimes we don't want to trace a function with the function 711 * graph tracer but we want them to keep traced by the usual function 712 * tracer if the function graph tracer is not configured. 713 */ 714 #define __notrace_funcgraph notrace 715 716 /* 717 * We want to which function is an entrypoint of a hardirq. 718 * That will help us to put a signal on output. 719 */ 720 #define __irq_entry __attribute__((__section__(".irqentry.text"))) 721 722 /* Limits of hardirq entrypoints */ 723 extern char __irqentry_text_start[]; 724 extern char __irqentry_text_end[]; 725 726 #define FTRACE_NOTRACE_DEPTH 65536 727 #define FTRACE_RETFUNC_DEPTH 50 728 #define FTRACE_RETSTACK_ALLOC_SIZE 32 729 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 730 trace_func_graph_ent_t entryfunc); 731 732 extern bool ftrace_graph_is_dead(void); 733 extern void ftrace_graph_stop(void); 734 735 /* The current handlers in use */ 736 extern trace_func_graph_ret_t ftrace_graph_return; 737 extern trace_func_graph_ent_t ftrace_graph_entry; 738 739 extern void unregister_ftrace_graph(void); 740 741 extern void ftrace_graph_init_task(struct task_struct *t); 742 extern void ftrace_graph_exit_task(struct task_struct *t); 743 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 744 745 static inline int task_curr_ret_stack(struct task_struct *t) 746 { 747 return t->curr_ret_stack; 748 } 749 750 static inline void pause_graph_tracing(void) 751 { 752 atomic_inc(¤t->tracing_graph_pause); 753 } 754 755 static inline void unpause_graph_tracing(void) 756 { 757 atomic_dec(¤t->tracing_graph_pause); 758 } 759 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 760 761 #define __notrace_funcgraph 762 #define __irq_entry 763 #define INIT_FTRACE_GRAPH 764 765 static inline void ftrace_graph_init_task(struct task_struct *t) { } 766 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 767 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 768 769 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 770 trace_func_graph_ent_t entryfunc) 771 { 772 return -1; 773 } 774 static inline void unregister_ftrace_graph(void) { } 775 776 static inline int task_curr_ret_stack(struct task_struct *tsk) 777 { 778 return -1; 779 } 780 781 static inline void pause_graph_tracing(void) { } 782 static inline void unpause_graph_tracing(void) { } 783 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 784 785 #ifdef CONFIG_TRACING 786 787 /* flags for current->trace */ 788 enum { 789 TSK_TRACE_FL_TRACE_BIT = 0, 790 TSK_TRACE_FL_GRAPH_BIT = 1, 791 }; 792 enum { 793 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 794 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 795 }; 796 797 static inline void set_tsk_trace_trace(struct task_struct *tsk) 798 { 799 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 800 } 801 802 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 803 { 804 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 805 } 806 807 static inline int test_tsk_trace_trace(struct task_struct *tsk) 808 { 809 return tsk->trace & TSK_TRACE_FL_TRACE; 810 } 811 812 static inline void set_tsk_trace_graph(struct task_struct *tsk) 813 { 814 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 815 } 816 817 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 818 { 819 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 820 } 821 822 static inline int test_tsk_trace_graph(struct task_struct *tsk) 823 { 824 return tsk->trace & TSK_TRACE_FL_GRAPH; 825 } 826 827 enum ftrace_dump_mode; 828 829 extern enum ftrace_dump_mode ftrace_dump_on_oops; 830 831 extern void disable_trace_on_warning(void); 832 extern int __disable_trace_on_warning; 833 834 #ifdef CONFIG_PREEMPT 835 #define INIT_TRACE_RECURSION .trace_recursion = 0, 836 #endif 837 838 #else /* CONFIG_TRACING */ 839 static inline void disable_trace_on_warning(void) { } 840 #endif /* CONFIG_TRACING */ 841 842 #ifndef INIT_TRACE_RECURSION 843 #define INIT_TRACE_RECURSION 844 #endif 845 846 #ifdef CONFIG_FTRACE_SYSCALLS 847 848 unsigned long arch_syscall_addr(int nr); 849 850 #endif /* CONFIG_FTRACE_SYSCALLS */ 851 852 #endif /* _LINUX_FTRACE_H */ 853