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