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 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 60 61 /* 62 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 63 * set in the flags member. 64 * 65 * ENABLED - set/unset when ftrace_ops is registered/unregistered 66 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 67 * allocated ftrace_ops which need special care 68 * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops 69 * could be controled by following calls: 70 * ftrace_function_local_enable 71 * ftrace_function_local_disable 72 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 73 * and passed to the callback. If this flag is set, but the 74 * architecture does not support passing regs 75 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 76 * ftrace_ops will fail to register, unless the next flag 77 * is set. 78 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 79 * handler can handle an arch that does not save regs 80 * (the handler tests if regs == NULL), then it can set 81 * this flag instead. It will not fail registering the ftrace_ops 82 * but, the regs field will be NULL if the arch does not support 83 * passing regs to the handler. 84 * Note, if this flag is set, the SAVE_REGS flag will automatically 85 * get set upon registering the ftrace_ops, if the arch supports it. 86 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure 87 * that the call back has its own recursion protection. If it does 88 * not set this, then the ftrace infrastructure will add recursion 89 * protection for the caller. 90 * STUB - The ftrace_ops is just a place holder. 91 * INITIALIZED - The ftrace_ops has already been initialized (first use time 92 * register_ftrace_function() is called, it will initialized the ops) 93 * DELETED - The ops are being deleted, do not let them be registered again. 94 * ADDING - The ops is in the process of being added. 95 * REMOVING - The ops is in the process of being removed. 96 * MODIFYING - The ops is in the process of changing its filter functions. 97 */ 98 enum { 99 FTRACE_OPS_FL_ENABLED = 1 << 0, 100 FTRACE_OPS_FL_DYNAMIC = 1 << 1, 101 FTRACE_OPS_FL_CONTROL = 1 << 2, 102 FTRACE_OPS_FL_SAVE_REGS = 1 << 3, 103 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 4, 104 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 5, 105 FTRACE_OPS_FL_STUB = 1 << 6, 106 FTRACE_OPS_FL_INITIALIZED = 1 << 7, 107 FTRACE_OPS_FL_DELETED = 1 << 8, 108 FTRACE_OPS_FL_ADDING = 1 << 9, 109 FTRACE_OPS_FL_REMOVING = 1 << 10, 110 FTRACE_OPS_FL_MODIFYING = 1 << 11, 111 }; 112 113 #ifdef CONFIG_DYNAMIC_FTRACE 114 /* The hash used to know what functions callbacks trace */ 115 struct ftrace_ops_hash { 116 struct ftrace_hash *notrace_hash; 117 struct ftrace_hash *filter_hash; 118 struct mutex regex_lock; 119 }; 120 #endif 121 122 /* 123 * Note, ftrace_ops can be referenced outside of RCU protection. 124 * (Although, for perf, the control ops prevent that). If ftrace_ops is 125 * allocated and not part of kernel core data, the unregistering of it will 126 * perform a scheduling on all CPUs to make sure that there are no more users. 127 * Depending on the load of the system that may take a bit of time. 128 * 129 * Any private data added must also take care not to be freed and if private 130 * data is added to a ftrace_ops that is in core code, the user of the 131 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 132 */ 133 struct ftrace_ops { 134 ftrace_func_t func; 135 struct ftrace_ops *next; 136 unsigned long flags; 137 void *private; 138 int __percpu *disabled; 139 #ifdef CONFIG_DYNAMIC_FTRACE 140 int nr_trampolines; 141 struct ftrace_ops_hash local_hash; 142 struct ftrace_ops_hash *func_hash; 143 struct ftrace_ops_hash old_hash; 144 unsigned long trampoline; 145 #endif 146 }; 147 148 /* 149 * Type of the current tracing. 150 */ 151 enum ftrace_tracing_type_t { 152 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 153 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 154 }; 155 156 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 157 extern enum ftrace_tracing_type_t ftrace_tracing_type; 158 159 /* 160 * The ftrace_ops must be a static and should also 161 * be read_mostly. These functions do modify read_mostly variables 162 * so use them sparely. Never free an ftrace_op or modify the 163 * next pointer after it has been registered. Even after unregistering 164 * it, the next pointer may still be used internally. 165 */ 166 int register_ftrace_function(struct ftrace_ops *ops); 167 int unregister_ftrace_function(struct ftrace_ops *ops); 168 void clear_ftrace_function(void); 169 170 /** 171 * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu 172 * 173 * This function enables tracing on current cpu by decreasing 174 * the per cpu control variable. 175 * It must be called with preemption disabled and only on ftrace_ops 176 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 177 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 178 */ 179 static inline void ftrace_function_local_enable(struct ftrace_ops *ops) 180 { 181 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 182 return; 183 184 (*this_cpu_ptr(ops->disabled))--; 185 } 186 187 /** 188 * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu 189 * 190 * This function enables tracing on current cpu by decreasing 191 * the per cpu control variable. 192 * It must be called with preemption disabled and only on ftrace_ops 193 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 194 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 195 */ 196 static inline void ftrace_function_local_disable(struct ftrace_ops *ops) 197 { 198 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) 199 return; 200 201 (*this_cpu_ptr(ops->disabled))++; 202 } 203 204 /** 205 * ftrace_function_local_disabled - returns ftrace_ops disabled value 206 * on current cpu 207 * 208 * This function returns value of ftrace_ops::disabled on current cpu. 209 * It must be called with preemption disabled and only on ftrace_ops 210 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption 211 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 212 */ 213 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) 214 { 215 WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)); 216 return *this_cpu_ptr(ops->disabled); 217 } 218 219 extern void ftrace_stub(unsigned long a0, unsigned long a1, 220 struct ftrace_ops *op, struct pt_regs *regs); 221 222 #else /* !CONFIG_FUNCTION_TRACER */ 223 /* 224 * (un)register_ftrace_function must be a macro since the ops parameter 225 * must not be evaluated. 226 */ 227 #define register_ftrace_function(ops) ({ 0; }) 228 #define unregister_ftrace_function(ops) ({ 0; }) 229 static inline int ftrace_nr_registered_ops(void) 230 { 231 return 0; 232 } 233 static inline void clear_ftrace_function(void) { } 234 static inline void ftrace_kill(void) { } 235 #endif /* CONFIG_FUNCTION_TRACER */ 236 237 #ifdef CONFIG_STACK_TRACER 238 extern int stack_tracer_enabled; 239 int 240 stack_trace_sysctl(struct ctl_table *table, int write, 241 void __user *buffer, size_t *lenp, 242 loff_t *ppos); 243 #endif 244 245 struct ftrace_func_command { 246 struct list_head list; 247 char *name; 248 int (*func)(struct ftrace_hash *hash, 249 char *func, char *cmd, 250 char *params, int enable); 251 }; 252 253 #ifdef CONFIG_DYNAMIC_FTRACE 254 255 int ftrace_arch_code_modify_prepare(void); 256 int ftrace_arch_code_modify_post_process(void); 257 258 void ftrace_bug(int err, unsigned long ip); 259 260 struct seq_file; 261 262 struct ftrace_probe_ops { 263 void (*func)(unsigned long ip, 264 unsigned long parent_ip, 265 void **data); 266 int (*init)(struct ftrace_probe_ops *ops, 267 unsigned long ip, void **data); 268 void (*free)(struct ftrace_probe_ops *ops, 269 unsigned long ip, void **data); 270 int (*print)(struct seq_file *m, 271 unsigned long ip, 272 struct ftrace_probe_ops *ops, 273 void *data); 274 }; 275 276 extern int 277 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 278 void *data); 279 extern void 280 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 281 void *data); 282 extern void 283 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops); 284 extern void unregister_ftrace_function_probe_all(char *glob); 285 286 extern int ftrace_text_reserved(const void *start, const void *end); 287 288 extern int ftrace_nr_registered_ops(void); 289 290 /* 291 * The dyn_ftrace record's flags field is split into two parts. 292 * the first part which is '0-FTRACE_REF_MAX' is a counter of 293 * the number of callbacks that have registered the function that 294 * the dyn_ftrace descriptor represents. 295 * 296 * The second part is a mask: 297 * ENABLED - the function is being traced 298 * REGS - the record wants the function to save regs 299 * REGS_EN - the function is set up to save regs. 300 * 301 * When a new ftrace_ops is registered and wants a function to save 302 * pt_regs, the rec->flag REGS is set. When the function has been 303 * set up to save regs, the REG_EN flag is set. Once a function 304 * starts saving regs it will do so until all ftrace_ops are removed 305 * from tracing that function. 306 */ 307 enum { 308 FTRACE_FL_ENABLED = (1UL << 31), 309 FTRACE_FL_REGS = (1UL << 30), 310 FTRACE_FL_REGS_EN = (1UL << 29), 311 FTRACE_FL_TRAMP = (1UL << 28), 312 FTRACE_FL_TRAMP_EN = (1UL << 27), 313 }; 314 315 #define FTRACE_REF_MAX_SHIFT 27 316 #define FTRACE_FL_BITS 5 317 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 318 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 319 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 320 321 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 322 323 struct dyn_ftrace { 324 unsigned long ip; /* address of mcount call-site */ 325 unsigned long flags; 326 struct dyn_arch_ftrace arch; 327 }; 328 329 int ftrace_force_update(void); 330 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 331 int remove, int reset); 332 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 333 int len, int reset); 334 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 335 int len, int reset); 336 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 337 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 338 void ftrace_free_filter(struct ftrace_ops *ops); 339 340 int register_ftrace_command(struct ftrace_func_command *cmd); 341 int unregister_ftrace_command(struct ftrace_func_command *cmd); 342 343 enum { 344 FTRACE_UPDATE_CALLS = (1 << 0), 345 FTRACE_DISABLE_CALLS = (1 << 1), 346 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 347 FTRACE_START_FUNC_RET = (1 << 3), 348 FTRACE_STOP_FUNC_RET = (1 << 4), 349 }; 350 351 /* 352 * The FTRACE_UPDATE_* enum is used to pass information back 353 * from the ftrace_update_record() and ftrace_test_record() 354 * functions. These are called by the code update routines 355 * to find out what is to be done for a given function. 356 * 357 * IGNORE - The function is already what we want it to be 358 * MAKE_CALL - Start tracing the function 359 * MODIFY_CALL - Stop saving regs for the function 360 * MAKE_NOP - Stop tracing the function 361 */ 362 enum { 363 FTRACE_UPDATE_IGNORE, 364 FTRACE_UPDATE_MAKE_CALL, 365 FTRACE_UPDATE_MODIFY_CALL, 366 FTRACE_UPDATE_MAKE_NOP, 367 }; 368 369 enum { 370 FTRACE_ITER_FILTER = (1 << 0), 371 FTRACE_ITER_NOTRACE = (1 << 1), 372 FTRACE_ITER_PRINTALL = (1 << 2), 373 FTRACE_ITER_DO_HASH = (1 << 3), 374 FTRACE_ITER_HASH = (1 << 4), 375 FTRACE_ITER_ENABLED = (1 << 5), 376 }; 377 378 void arch_ftrace_update_code(int command); 379 380 struct ftrace_rec_iter; 381 382 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 383 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 384 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 385 386 #define for_ftrace_rec_iter(iter) \ 387 for (iter = ftrace_rec_iter_start(); \ 388 iter; \ 389 iter = ftrace_rec_iter_next(iter)) 390 391 392 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 393 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 394 void ftrace_run_stop_machine(int command); 395 unsigned long ftrace_location(unsigned long ip); 396 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 397 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 398 399 extern ftrace_func_t ftrace_trace_function; 400 401 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 402 struct inode *inode, struct file *file); 403 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 404 size_t cnt, loff_t *ppos); 405 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 406 size_t cnt, loff_t *ppos); 407 int ftrace_regex_release(struct inode *inode, struct file *file); 408 409 void __init 410 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 411 412 /* defined in arch */ 413 extern int ftrace_ip_converted(unsigned long ip); 414 extern int ftrace_dyn_arch_init(void); 415 extern void ftrace_replace_code(int enable); 416 extern int ftrace_update_ftrace_func(ftrace_func_t func); 417 extern void ftrace_caller(void); 418 extern void ftrace_regs_caller(void); 419 extern void ftrace_call(void); 420 extern void ftrace_regs_call(void); 421 extern void mcount_call(void); 422 423 void ftrace_modify_all_code(int command); 424 425 #ifndef FTRACE_ADDR 426 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 427 #endif 428 429 #ifndef FTRACE_GRAPH_ADDR 430 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 431 #endif 432 433 #ifndef FTRACE_REGS_ADDR 434 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 435 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 436 #else 437 # define FTRACE_REGS_ADDR FTRACE_ADDR 438 #endif 439 #endif 440 441 /* 442 * If an arch would like functions that are only traced 443 * by the function graph tracer to jump directly to its own 444 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 445 * to be that address to jump to. 446 */ 447 #ifndef FTRACE_GRAPH_TRAMP_ADDR 448 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 449 #endif 450 451 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 452 extern void ftrace_graph_caller(void); 453 extern int ftrace_enable_ftrace_graph_caller(void); 454 extern int ftrace_disable_ftrace_graph_caller(void); 455 #else 456 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 457 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 458 #endif 459 460 /** 461 * ftrace_make_nop - convert code into nop 462 * @mod: module structure if called by module load initialization 463 * @rec: the mcount call site record 464 * @addr: the address that the call site should be calling 465 * 466 * This is a very sensitive operation and great care needs 467 * to be taken by the arch. The operation should carefully 468 * read the location, check to see if what is read is indeed 469 * what we expect it to be, and then on success of the compare, 470 * it should write to the location. 471 * 472 * The code segment at @rec->ip should be a caller to @addr 473 * 474 * Return must be: 475 * 0 on success 476 * -EFAULT on error reading the location 477 * -EINVAL on a failed compare of the contents 478 * -EPERM on error writing to the location 479 * Any other value will be considered a failure. 480 */ 481 extern int ftrace_make_nop(struct module *mod, 482 struct dyn_ftrace *rec, unsigned long addr); 483 484 /** 485 * ftrace_make_call - convert a nop call site into a call to addr 486 * @rec: the mcount call site record 487 * @addr: the address that the call site should call 488 * 489 * This is a very sensitive operation and great care needs 490 * to be taken by the arch. The operation should carefully 491 * read the location, check to see if what is read is indeed 492 * what we expect it to be, and then on success of the compare, 493 * it should write to the location. 494 * 495 * The code segment at @rec->ip should be a nop 496 * 497 * Return must be: 498 * 0 on success 499 * -EFAULT on error reading the location 500 * -EINVAL on a failed compare of the contents 501 * -EPERM on error writing to the location 502 * Any other value will be considered a failure. 503 */ 504 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 505 506 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 507 /** 508 * ftrace_modify_call - convert from one addr to another (no nop) 509 * @rec: the mcount call site record 510 * @old_addr: the address expected to be currently called to 511 * @addr: the address to change to 512 * 513 * This is a very sensitive operation and great care needs 514 * to be taken by the arch. The operation should carefully 515 * read the location, check to see if what is read is indeed 516 * what we expect it to be, and then on success of the compare, 517 * it should write to the location. 518 * 519 * The code segment at @rec->ip should be a caller to @old_addr 520 * 521 * Return must be: 522 * 0 on success 523 * -EFAULT on error reading the location 524 * -EINVAL on a failed compare of the contents 525 * -EPERM on error writing to the location 526 * Any other value will be considered a failure. 527 */ 528 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 529 unsigned long addr); 530 #else 531 /* Should never be called */ 532 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 533 unsigned long addr) 534 { 535 return -EINVAL; 536 } 537 #endif 538 539 /* May be defined in arch */ 540 extern int ftrace_arch_read_dyn_info(char *buf, int size); 541 542 extern int skip_trace(unsigned long ip); 543 extern void ftrace_module_init(struct module *mod); 544 545 extern void ftrace_disable_daemon(void); 546 extern void ftrace_enable_daemon(void); 547 #else /* CONFIG_DYNAMIC_FTRACE */ 548 static inline int skip_trace(unsigned long ip) { return 0; } 549 static inline int ftrace_force_update(void) { return 0; } 550 static inline void ftrace_disable_daemon(void) { } 551 static inline void ftrace_enable_daemon(void) { } 552 static inline void ftrace_release_mod(struct module *mod) {} 553 static inline void ftrace_module_init(struct module *mod) {} 554 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd) 555 { 556 return -EINVAL; 557 } 558 static inline __init int unregister_ftrace_command(char *cmd_name) 559 { 560 return -EINVAL; 561 } 562 static inline int ftrace_text_reserved(const void *start, const void *end) 563 { 564 return 0; 565 } 566 static inline unsigned long ftrace_location(unsigned long ip) 567 { 568 return 0; 569 } 570 571 /* 572 * Again users of functions that have ftrace_ops may not 573 * have them defined when ftrace is not enabled, but these 574 * functions may still be called. Use a macro instead of inline. 575 */ 576 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 577 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 578 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 579 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 580 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 581 #define ftrace_free_filter(ops) do { } while (0) 582 583 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 584 size_t cnt, loff_t *ppos) { return -ENODEV; } 585 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 586 size_t cnt, loff_t *ppos) { return -ENODEV; } 587 static inline int 588 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 589 #endif /* CONFIG_DYNAMIC_FTRACE */ 590 591 /* totally disable ftrace - can not re-enable after this */ 592 void ftrace_kill(void); 593 594 static inline void tracer_disable(void) 595 { 596 #ifdef CONFIG_FUNCTION_TRACER 597 ftrace_enabled = 0; 598 #endif 599 } 600 601 /* 602 * Ftrace disable/restore without lock. Some synchronization mechanism 603 * must be used to prevent ftrace_enabled to be changed between 604 * disable/restore. 605 */ 606 static inline int __ftrace_enabled_save(void) 607 { 608 #ifdef CONFIG_FUNCTION_TRACER 609 int saved_ftrace_enabled = ftrace_enabled; 610 ftrace_enabled = 0; 611 return saved_ftrace_enabled; 612 #else 613 return 0; 614 #endif 615 } 616 617 static inline void __ftrace_enabled_restore(int enabled) 618 { 619 #ifdef CONFIG_FUNCTION_TRACER 620 ftrace_enabled = enabled; 621 #endif 622 } 623 624 /* All archs should have this, but we define it for consistency */ 625 #ifndef ftrace_return_address0 626 # define ftrace_return_address0 __builtin_return_address(0) 627 #endif 628 629 /* Archs may use other ways for ADDR1 and beyond */ 630 #ifndef ftrace_return_address 631 # ifdef CONFIG_FRAME_POINTER 632 # define ftrace_return_address(n) __builtin_return_address(n) 633 # else 634 # define ftrace_return_address(n) 0UL 635 # endif 636 #endif 637 638 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 639 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 640 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 641 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 642 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 643 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 644 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 645 646 #ifdef CONFIG_IRQSOFF_TRACER 647 extern void time_hardirqs_on(unsigned long a0, unsigned long a1); 648 extern void time_hardirqs_off(unsigned long a0, unsigned long a1); 649 #else 650 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } 651 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } 652 #endif 653 654 #ifdef CONFIG_PREEMPT_TRACER 655 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 656 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 657 #else 658 /* 659 * Use defines instead of static inlines because some arches will make code out 660 * of the CALLER_ADDR, when we really want these to be a real nop. 661 */ 662 # define trace_preempt_on(a0, a1) do { } while (0) 663 # define trace_preempt_off(a0, a1) do { } while (0) 664 #endif 665 666 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 667 extern void ftrace_init(void); 668 #else 669 static inline void ftrace_init(void) { } 670 #endif 671 672 /* 673 * Structure that defines an entry function trace. 674 */ 675 struct ftrace_graph_ent { 676 unsigned long func; /* Current function */ 677 int depth; 678 }; 679 680 /* 681 * Structure that defines a return function trace. 682 */ 683 struct ftrace_graph_ret { 684 unsigned long func; /* Current function */ 685 unsigned long long calltime; 686 unsigned long long rettime; 687 /* Number of functions that overran the depth limit for current task */ 688 unsigned long overrun; 689 int depth; 690 }; 691 692 /* Type of the callback handlers for tracing function graph*/ 693 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 694 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 695 696 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 697 698 /* for init task */ 699 #define INIT_FTRACE_GRAPH .ret_stack = NULL, 700 701 /* 702 * Stack of return addresses for functions 703 * of a thread. 704 * Used in struct thread_info 705 */ 706 struct ftrace_ret_stack { 707 unsigned long ret; 708 unsigned long func; 709 unsigned long long calltime; 710 unsigned long long subtime; 711 unsigned long fp; 712 }; 713 714 /* 715 * Primary handler of a function return. 716 * It relays on ftrace_return_to_handler. 717 * Defined in entry_32/64.S 718 */ 719 extern void return_to_handler(void); 720 721 extern int 722 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 723 unsigned long frame_pointer); 724 725 /* 726 * Sometimes we don't want to trace a function with the function 727 * graph tracer but we want them to keep traced by the usual function 728 * tracer if the function graph tracer is not configured. 729 */ 730 #define __notrace_funcgraph notrace 731 732 /* 733 * We want to which function is an entrypoint of a hardirq. 734 * That will help us to put a signal on output. 735 */ 736 #define __irq_entry __attribute__((__section__(".irqentry.text"))) 737 738 /* Limits of hardirq entrypoints */ 739 extern char __irqentry_text_start[]; 740 extern char __irqentry_text_end[]; 741 742 #define FTRACE_NOTRACE_DEPTH 65536 743 #define FTRACE_RETFUNC_DEPTH 50 744 #define FTRACE_RETSTACK_ALLOC_SIZE 32 745 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 746 trace_func_graph_ent_t entryfunc); 747 748 extern bool ftrace_graph_is_dead(void); 749 extern void ftrace_graph_stop(void); 750 751 /* The current handlers in use */ 752 extern trace_func_graph_ret_t ftrace_graph_return; 753 extern trace_func_graph_ent_t ftrace_graph_entry; 754 755 extern void unregister_ftrace_graph(void); 756 757 extern void ftrace_graph_init_task(struct task_struct *t); 758 extern void ftrace_graph_exit_task(struct task_struct *t); 759 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 760 761 static inline int task_curr_ret_stack(struct task_struct *t) 762 { 763 return t->curr_ret_stack; 764 } 765 766 static inline void pause_graph_tracing(void) 767 { 768 atomic_inc(¤t->tracing_graph_pause); 769 } 770 771 static inline void unpause_graph_tracing(void) 772 { 773 atomic_dec(¤t->tracing_graph_pause); 774 } 775 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 776 777 #define __notrace_funcgraph 778 #define __irq_entry 779 #define INIT_FTRACE_GRAPH 780 781 static inline void ftrace_graph_init_task(struct task_struct *t) { } 782 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 783 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 784 785 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 786 trace_func_graph_ent_t entryfunc) 787 { 788 return -1; 789 } 790 static inline void unregister_ftrace_graph(void) { } 791 792 static inline int task_curr_ret_stack(struct task_struct *tsk) 793 { 794 return -1; 795 } 796 797 static inline void pause_graph_tracing(void) { } 798 static inline void unpause_graph_tracing(void) { } 799 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 800 801 #ifdef CONFIG_TRACING 802 803 /* flags for current->trace */ 804 enum { 805 TSK_TRACE_FL_TRACE_BIT = 0, 806 TSK_TRACE_FL_GRAPH_BIT = 1, 807 }; 808 enum { 809 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 810 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 811 }; 812 813 static inline void set_tsk_trace_trace(struct task_struct *tsk) 814 { 815 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 816 } 817 818 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 819 { 820 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 821 } 822 823 static inline int test_tsk_trace_trace(struct task_struct *tsk) 824 { 825 return tsk->trace & TSK_TRACE_FL_TRACE; 826 } 827 828 static inline void set_tsk_trace_graph(struct task_struct *tsk) 829 { 830 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 831 } 832 833 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 834 { 835 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 836 } 837 838 static inline int test_tsk_trace_graph(struct task_struct *tsk) 839 { 840 return tsk->trace & TSK_TRACE_FL_GRAPH; 841 } 842 843 enum ftrace_dump_mode; 844 845 extern enum ftrace_dump_mode ftrace_dump_on_oops; 846 847 extern void disable_trace_on_warning(void); 848 extern int __disable_trace_on_warning; 849 850 #ifdef CONFIG_PREEMPT 851 #define INIT_TRACE_RECURSION .trace_recursion = 0, 852 #endif 853 854 #else /* CONFIG_TRACING */ 855 static inline void disable_trace_on_warning(void) { } 856 #endif /* CONFIG_TRACING */ 857 858 #ifndef INIT_TRACE_RECURSION 859 #define INIT_TRACE_RECURSION 860 #endif 861 862 #ifdef CONFIG_FTRACE_SYSCALLS 863 864 unsigned long arch_syscall_addr(int nr); 865 866 #endif /* CONFIG_FTRACE_SYSCALLS */ 867 868 #endif /* _LINUX_FTRACE_H */ 869