1 /* 2 * Ftrace header. For implementation details beyond the random comments 3 * scattered below, see: Documentation/trace/ftrace-design.txt 4 */ 5 6 #ifndef _LINUX_FTRACE_H 7 #define _LINUX_FTRACE_H 8 9 #include <linux/trace_clock.h> 10 #include <linux/kallsyms.h> 11 #include <linux/linkage.h> 12 #include <linux/bitops.h> 13 #include <linux/ptrace.h> 14 #include <linux/ktime.h> 15 #include <linux/sched.h> 16 #include <linux/types.h> 17 #include <linux/init.h> 18 #include <linux/fs.h> 19 20 #include <asm/ftrace.h> 21 22 /* 23 * If the arch supports passing the variable contents of 24 * function_trace_op as the third parameter back from the 25 * mcount call, then the arch should define this as 1. 26 */ 27 #ifndef ARCH_SUPPORTS_FTRACE_OPS 28 #define ARCH_SUPPORTS_FTRACE_OPS 0 29 #endif 30 31 /* 32 * If the arch's mcount caller does not support all of ftrace's 33 * features, then it must call an indirect function that 34 * does. Or at least does enough to prevent any unwelcomed side effects. 35 */ 36 #if !ARCH_SUPPORTS_FTRACE_OPS 37 # define FTRACE_FORCE_LIST_FUNC 1 38 #else 39 # define FTRACE_FORCE_LIST_FUNC 0 40 #endif 41 42 /* Main tracing buffer and events set up */ 43 #ifdef CONFIG_TRACING 44 void trace_init(void); 45 #else 46 static inline void trace_init(void) { } 47 #endif 48 49 struct module; 50 struct ftrace_hash; 51 52 #ifdef CONFIG_FUNCTION_TRACER 53 54 extern int ftrace_enabled; 55 extern int 56 ftrace_enable_sysctl(struct ctl_table *table, int write, 57 void __user *buffer, size_t *lenp, 58 loff_t *ppos); 59 60 struct ftrace_ops; 61 62 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 63 struct ftrace_ops *op, struct pt_regs *regs); 64 65 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 66 67 /* 68 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 69 * set in the flags member. 70 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION_SAFE, STUB and 71 * IPMODIFY are a kind of attribute flags which can be set only before 72 * registering the ftrace_ops, and can not be modified while registered. 73 * Changing those attribute flags after regsitering ftrace_ops will 74 * cause unexpected results. 75 * 76 * ENABLED - set/unset when ftrace_ops is registered/unregistered 77 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 78 * allocated ftrace_ops which need special care 79 * PER_CPU - set manualy by ftrace_ops user to denote the ftrace_ops 80 * could be controlled by following calls: 81 * ftrace_function_local_enable 82 * ftrace_function_local_disable 83 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 84 * and passed to the callback. If this flag is set, but the 85 * architecture does not support passing regs 86 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 87 * ftrace_ops will fail to register, unless the next flag 88 * is set. 89 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 90 * handler can handle an arch that does not save regs 91 * (the handler tests if regs == NULL), then it can set 92 * this flag instead. It will not fail registering the ftrace_ops 93 * but, the regs field will be NULL if the arch does not support 94 * passing regs to the handler. 95 * Note, if this flag is set, the SAVE_REGS flag will automatically 96 * get set upon registering the ftrace_ops, if the arch supports it. 97 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure 98 * that the call back has its own recursion protection. If it does 99 * not set this, then the ftrace infrastructure will add recursion 100 * protection for the caller. 101 * STUB - The ftrace_ops is just a place holder. 102 * INITIALIZED - The ftrace_ops has already been initialized (first use time 103 * register_ftrace_function() is called, it will initialized the ops) 104 * DELETED - The ops are being deleted, do not let them be registered again. 105 * ADDING - The ops is in the process of being added. 106 * REMOVING - The ops is in the process of being removed. 107 * MODIFYING - The ops is in the process of changing its filter functions. 108 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 109 * The arch specific code sets this flag when it allocated a 110 * trampoline. This lets the arch know that it can update the 111 * trampoline in case the callback function changes. 112 * The ftrace_ops trampoline can be set by the ftrace users, and 113 * in such cases the arch must not modify it. Only the arch ftrace 114 * core code should set this flag. 115 * IPMODIFY - The ops can modify the IP register. This can only be set with 116 * SAVE_REGS. If another ops with this flag set is already registered 117 * for any of the functions that this ops will be registered for, then 118 * this ops will fail to register or set_filter_ip. 119 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 120 */ 121 enum { 122 FTRACE_OPS_FL_ENABLED = 1 << 0, 123 FTRACE_OPS_FL_DYNAMIC = 1 << 1, 124 FTRACE_OPS_FL_PER_CPU = 1 << 2, 125 FTRACE_OPS_FL_SAVE_REGS = 1 << 3, 126 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 4, 127 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 5, 128 FTRACE_OPS_FL_STUB = 1 << 6, 129 FTRACE_OPS_FL_INITIALIZED = 1 << 7, 130 FTRACE_OPS_FL_DELETED = 1 << 8, 131 FTRACE_OPS_FL_ADDING = 1 << 9, 132 FTRACE_OPS_FL_REMOVING = 1 << 10, 133 FTRACE_OPS_FL_MODIFYING = 1 << 11, 134 FTRACE_OPS_FL_ALLOC_TRAMP = 1 << 12, 135 FTRACE_OPS_FL_IPMODIFY = 1 << 13, 136 FTRACE_OPS_FL_PID = 1 << 14, 137 FTRACE_OPS_FL_RCU = 1 << 15, 138 }; 139 140 #ifdef CONFIG_DYNAMIC_FTRACE 141 /* The hash used to know what functions callbacks trace */ 142 struct ftrace_ops_hash { 143 struct ftrace_hash *notrace_hash; 144 struct ftrace_hash *filter_hash; 145 struct mutex regex_lock; 146 }; 147 #endif 148 149 /* 150 * Note, ftrace_ops can be referenced outside of RCU protection, unless 151 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel 152 * core data, the unregistering of it will perform a scheduling on all CPUs 153 * to make sure that there are no more users. Depending on the load of the 154 * system that may take a bit of time. 155 * 156 * Any private data added must also take care not to be freed and if private 157 * data is added to a ftrace_ops that is in core code, the user of the 158 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 159 */ 160 struct ftrace_ops { 161 ftrace_func_t func; 162 struct ftrace_ops *next; 163 unsigned long flags; 164 void *private; 165 ftrace_func_t saved_func; 166 int __percpu *disabled; 167 #ifdef CONFIG_DYNAMIC_FTRACE 168 struct ftrace_ops_hash local_hash; 169 struct ftrace_ops_hash *func_hash; 170 struct ftrace_ops_hash old_hash; 171 unsigned long trampoline; 172 unsigned long trampoline_size; 173 #endif 174 }; 175 176 /* 177 * Type of the current tracing. 178 */ 179 enum ftrace_tracing_type_t { 180 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 181 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 182 }; 183 184 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 185 extern enum ftrace_tracing_type_t ftrace_tracing_type; 186 187 /* 188 * The ftrace_ops must be a static and should also 189 * be read_mostly. These functions do modify read_mostly variables 190 * so use them sparely. Never free an ftrace_op or modify the 191 * next pointer after it has been registered. Even after unregistering 192 * it, the next pointer may still be used internally. 193 */ 194 int register_ftrace_function(struct ftrace_ops *ops); 195 int unregister_ftrace_function(struct ftrace_ops *ops); 196 void clear_ftrace_function(void); 197 198 /** 199 * ftrace_function_local_enable - enable ftrace_ops on current cpu 200 * 201 * This function enables tracing on current cpu by decreasing 202 * the per cpu control variable. 203 * It must be called with preemption disabled and only on ftrace_ops 204 * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption 205 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 206 */ 207 static inline void ftrace_function_local_enable(struct ftrace_ops *ops) 208 { 209 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU))) 210 return; 211 212 (*this_cpu_ptr(ops->disabled))--; 213 } 214 215 /** 216 * ftrace_function_local_disable - disable ftrace_ops on current cpu 217 * 218 * This function disables tracing on current cpu by increasing 219 * the per cpu control variable. 220 * It must be called with preemption disabled and only on ftrace_ops 221 * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption 222 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 223 */ 224 static inline void ftrace_function_local_disable(struct ftrace_ops *ops) 225 { 226 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU))) 227 return; 228 229 (*this_cpu_ptr(ops->disabled))++; 230 } 231 232 /** 233 * ftrace_function_local_disabled - returns ftrace_ops disabled value 234 * on current cpu 235 * 236 * This function returns value of ftrace_ops::disabled on current cpu. 237 * It must be called with preemption disabled and only on ftrace_ops 238 * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption 239 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 240 */ 241 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) 242 { 243 WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)); 244 return *this_cpu_ptr(ops->disabled); 245 } 246 247 extern void ftrace_stub(unsigned long a0, unsigned long a1, 248 struct ftrace_ops *op, struct pt_regs *regs); 249 250 #else /* !CONFIG_FUNCTION_TRACER */ 251 /* 252 * (un)register_ftrace_function must be a macro since the ops parameter 253 * must not be evaluated. 254 */ 255 #define register_ftrace_function(ops) ({ 0; }) 256 #define unregister_ftrace_function(ops) ({ 0; }) 257 static inline int ftrace_nr_registered_ops(void) 258 { 259 return 0; 260 } 261 static inline void clear_ftrace_function(void) { } 262 static inline void ftrace_kill(void) { } 263 #endif /* CONFIG_FUNCTION_TRACER */ 264 265 #ifdef CONFIG_STACK_TRACER 266 267 #define STACK_TRACE_ENTRIES 500 268 269 struct stack_trace; 270 271 extern unsigned stack_trace_index[]; 272 extern struct stack_trace stack_trace_max; 273 extern unsigned long stack_trace_max_size; 274 extern arch_spinlock_t stack_trace_max_lock; 275 276 extern int stack_tracer_enabled; 277 void stack_trace_print(void); 278 int 279 stack_trace_sysctl(struct ctl_table *table, int write, 280 void __user *buffer, size_t *lenp, 281 loff_t *ppos); 282 #endif 283 284 struct ftrace_func_command { 285 struct list_head list; 286 char *name; 287 int (*func)(struct ftrace_hash *hash, 288 char *func, char *cmd, 289 char *params, int enable); 290 }; 291 292 #ifdef CONFIG_DYNAMIC_FTRACE 293 294 int ftrace_arch_code_modify_prepare(void); 295 int ftrace_arch_code_modify_post_process(void); 296 297 struct dyn_ftrace; 298 299 enum ftrace_bug_type { 300 FTRACE_BUG_UNKNOWN, 301 FTRACE_BUG_INIT, 302 FTRACE_BUG_NOP, 303 FTRACE_BUG_CALL, 304 FTRACE_BUG_UPDATE, 305 }; 306 extern enum ftrace_bug_type ftrace_bug_type; 307 308 /* 309 * Archs can set this to point to a variable that holds the value that was 310 * expected at the call site before calling ftrace_bug(). 311 */ 312 extern const void *ftrace_expected; 313 314 void ftrace_bug(int err, struct dyn_ftrace *rec); 315 316 struct seq_file; 317 318 struct ftrace_probe_ops { 319 void (*func)(unsigned long ip, 320 unsigned long parent_ip, 321 void **data); 322 int (*init)(struct ftrace_probe_ops *ops, 323 unsigned long ip, void **data); 324 void (*free)(struct ftrace_probe_ops *ops, 325 unsigned long ip, void **data); 326 int (*print)(struct seq_file *m, 327 unsigned long ip, 328 struct ftrace_probe_ops *ops, 329 void *data); 330 }; 331 332 extern int 333 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 334 void *data); 335 extern void 336 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 337 void *data); 338 extern void 339 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops); 340 extern void unregister_ftrace_function_probe_all(char *glob); 341 342 extern int ftrace_text_reserved(const void *start, const void *end); 343 344 extern int ftrace_nr_registered_ops(void); 345 346 bool is_ftrace_trampoline(unsigned long addr); 347 348 /* 349 * The dyn_ftrace record's flags field is split into two parts. 350 * the first part which is '0-FTRACE_REF_MAX' is a counter of 351 * the number of callbacks that have registered the function that 352 * the dyn_ftrace descriptor represents. 353 * 354 * The second part is a mask: 355 * ENABLED - the function is being traced 356 * REGS - the record wants the function to save regs 357 * REGS_EN - the function is set up to save regs. 358 * IPMODIFY - the record allows for the IP address to be changed. 359 * DISABLED - the record is not ready to be touched yet 360 * 361 * When a new ftrace_ops is registered and wants a function to save 362 * pt_regs, the rec->flag REGS is set. When the function has been 363 * set up to save regs, the REG_EN flag is set. Once a function 364 * starts saving regs it will do so until all ftrace_ops are removed 365 * from tracing that function. 366 */ 367 enum { 368 FTRACE_FL_ENABLED = (1UL << 31), 369 FTRACE_FL_REGS = (1UL << 30), 370 FTRACE_FL_REGS_EN = (1UL << 29), 371 FTRACE_FL_TRAMP = (1UL << 28), 372 FTRACE_FL_TRAMP_EN = (1UL << 27), 373 FTRACE_FL_IPMODIFY = (1UL << 26), 374 FTRACE_FL_DISABLED = (1UL << 25), 375 }; 376 377 #define FTRACE_REF_MAX_SHIFT 25 378 #define FTRACE_FL_BITS 7 379 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 380 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 381 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 382 383 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 384 385 struct dyn_ftrace { 386 unsigned long ip; /* address of mcount call-site */ 387 unsigned long flags; 388 struct dyn_arch_ftrace arch; 389 }; 390 391 int ftrace_force_update(void); 392 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 393 int remove, int reset); 394 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 395 int len, int reset); 396 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 397 int len, int reset); 398 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 399 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 400 void ftrace_free_filter(struct ftrace_ops *ops); 401 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 402 403 int register_ftrace_command(struct ftrace_func_command *cmd); 404 int unregister_ftrace_command(struct ftrace_func_command *cmd); 405 406 enum { 407 FTRACE_UPDATE_CALLS = (1 << 0), 408 FTRACE_DISABLE_CALLS = (1 << 1), 409 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 410 FTRACE_START_FUNC_RET = (1 << 3), 411 FTRACE_STOP_FUNC_RET = (1 << 4), 412 }; 413 414 /* 415 * The FTRACE_UPDATE_* enum is used to pass information back 416 * from the ftrace_update_record() and ftrace_test_record() 417 * functions. These are called by the code update routines 418 * to find out what is to be done for a given function. 419 * 420 * IGNORE - The function is already what we want it to be 421 * MAKE_CALL - Start tracing the function 422 * MODIFY_CALL - Stop saving regs for the function 423 * MAKE_NOP - Stop tracing the function 424 */ 425 enum { 426 FTRACE_UPDATE_IGNORE, 427 FTRACE_UPDATE_MAKE_CALL, 428 FTRACE_UPDATE_MODIFY_CALL, 429 FTRACE_UPDATE_MAKE_NOP, 430 }; 431 432 enum { 433 FTRACE_ITER_FILTER = (1 << 0), 434 FTRACE_ITER_NOTRACE = (1 << 1), 435 FTRACE_ITER_PRINTALL = (1 << 2), 436 FTRACE_ITER_DO_HASH = (1 << 3), 437 FTRACE_ITER_HASH = (1 << 4), 438 FTRACE_ITER_ENABLED = (1 << 5), 439 }; 440 441 void arch_ftrace_update_code(int command); 442 443 struct ftrace_rec_iter; 444 445 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 446 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 447 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 448 449 #define for_ftrace_rec_iter(iter) \ 450 for (iter = ftrace_rec_iter_start(); \ 451 iter; \ 452 iter = ftrace_rec_iter_next(iter)) 453 454 455 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 456 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 457 void ftrace_run_stop_machine(int command); 458 unsigned long ftrace_location(unsigned long ip); 459 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 460 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 461 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 462 463 extern ftrace_func_t ftrace_trace_function; 464 465 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 466 struct inode *inode, struct file *file); 467 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 468 size_t cnt, loff_t *ppos); 469 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 470 size_t cnt, loff_t *ppos); 471 int ftrace_regex_release(struct inode *inode, struct file *file); 472 473 void __init 474 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 475 476 /* defined in arch */ 477 extern int ftrace_ip_converted(unsigned long ip); 478 extern int ftrace_dyn_arch_init(void); 479 extern void ftrace_replace_code(int enable); 480 extern int ftrace_update_ftrace_func(ftrace_func_t func); 481 extern void ftrace_caller(void); 482 extern void ftrace_regs_caller(void); 483 extern void ftrace_call(void); 484 extern void ftrace_regs_call(void); 485 extern void mcount_call(void); 486 487 void ftrace_modify_all_code(int command); 488 489 #ifndef FTRACE_ADDR 490 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 491 #endif 492 493 #ifndef FTRACE_GRAPH_ADDR 494 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 495 #endif 496 497 #ifndef FTRACE_REGS_ADDR 498 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 499 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 500 #else 501 # define FTRACE_REGS_ADDR FTRACE_ADDR 502 #endif 503 #endif 504 505 /* 506 * If an arch would like functions that are only traced 507 * by the function graph tracer to jump directly to its own 508 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 509 * to be that address to jump to. 510 */ 511 #ifndef FTRACE_GRAPH_TRAMP_ADDR 512 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 513 #endif 514 515 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 516 extern void ftrace_graph_caller(void); 517 extern int ftrace_enable_ftrace_graph_caller(void); 518 extern int ftrace_disable_ftrace_graph_caller(void); 519 #else 520 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 521 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 522 #endif 523 524 /** 525 * ftrace_make_nop - convert code into nop 526 * @mod: module structure if called by module load initialization 527 * @rec: the mcount call site record 528 * @addr: the address that the call site should be calling 529 * 530 * This is a very sensitive operation and great care needs 531 * to be taken by the arch. The operation should carefully 532 * read the location, check to see if what is read is indeed 533 * what we expect it to be, and then on success of the compare, 534 * it should write to the location. 535 * 536 * The code segment at @rec->ip should be a caller to @addr 537 * 538 * Return must be: 539 * 0 on success 540 * -EFAULT on error reading the location 541 * -EINVAL on a failed compare of the contents 542 * -EPERM on error writing to the location 543 * Any other value will be considered a failure. 544 */ 545 extern int ftrace_make_nop(struct module *mod, 546 struct dyn_ftrace *rec, unsigned long addr); 547 548 /** 549 * ftrace_make_call - convert a nop call site into a call to addr 550 * @rec: the mcount call site record 551 * @addr: the address that the call site should call 552 * 553 * This is a very sensitive operation and great care needs 554 * to be taken by the arch. The operation should carefully 555 * read the location, check to see if what is read is indeed 556 * what we expect it to be, and then on success of the compare, 557 * it should write to the location. 558 * 559 * The code segment at @rec->ip should be a nop 560 * 561 * Return must be: 562 * 0 on success 563 * -EFAULT on error reading the location 564 * -EINVAL on a failed compare of the contents 565 * -EPERM on error writing to the location 566 * Any other value will be considered a failure. 567 */ 568 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 569 570 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 571 /** 572 * ftrace_modify_call - convert from one addr to another (no nop) 573 * @rec: the mcount call site record 574 * @old_addr: the address expected to be currently called to 575 * @addr: the address to change to 576 * 577 * This is a very sensitive operation and great care needs 578 * to be taken by the arch. The operation should carefully 579 * read the location, check to see if what is read is indeed 580 * what we expect it to be, and then on success of the compare, 581 * it should write to the location. 582 * 583 * The code segment at @rec->ip should be a caller to @old_addr 584 * 585 * Return must be: 586 * 0 on success 587 * -EFAULT on error reading the location 588 * -EINVAL on a failed compare of the contents 589 * -EPERM on error writing to the location 590 * Any other value will be considered a failure. 591 */ 592 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 593 unsigned long addr); 594 #else 595 /* Should never be called */ 596 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 597 unsigned long addr) 598 { 599 return -EINVAL; 600 } 601 #endif 602 603 /* May be defined in arch */ 604 extern int ftrace_arch_read_dyn_info(char *buf, int size); 605 606 extern int skip_trace(unsigned long ip); 607 extern void ftrace_module_init(struct module *mod); 608 extern void ftrace_module_enable(struct module *mod); 609 extern void ftrace_release_mod(struct module *mod); 610 611 extern void ftrace_disable_daemon(void); 612 extern void ftrace_enable_daemon(void); 613 #else /* CONFIG_DYNAMIC_FTRACE */ 614 static inline int skip_trace(unsigned long ip) { return 0; } 615 static inline int ftrace_force_update(void) { return 0; } 616 static inline void ftrace_disable_daemon(void) { } 617 static inline void ftrace_enable_daemon(void) { } 618 static inline void ftrace_module_init(struct module *mod) { } 619 static inline void ftrace_module_enable(struct module *mod) { } 620 static inline void ftrace_release_mod(struct module *mod) { } 621 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd) 622 { 623 return -EINVAL; 624 } 625 static inline __init int unregister_ftrace_command(char *cmd_name) 626 { 627 return -EINVAL; 628 } 629 static inline int ftrace_text_reserved(const void *start, const void *end) 630 { 631 return 0; 632 } 633 static inline unsigned long ftrace_location(unsigned long ip) 634 { 635 return 0; 636 } 637 638 /* 639 * Again users of functions that have ftrace_ops may not 640 * have them defined when ftrace is not enabled, but these 641 * functions may still be called. Use a macro instead of inline. 642 */ 643 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 644 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 645 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 646 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 647 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 648 #define ftrace_free_filter(ops) do { } while (0) 649 #define ftrace_ops_set_global_filter(ops) do { } while (0) 650 651 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 652 size_t cnt, loff_t *ppos) { return -ENODEV; } 653 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 654 size_t cnt, loff_t *ppos) { return -ENODEV; } 655 static inline int 656 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 657 658 static inline bool is_ftrace_trampoline(unsigned long addr) 659 { 660 return false; 661 } 662 #endif /* CONFIG_DYNAMIC_FTRACE */ 663 664 /* totally disable ftrace - can not re-enable after this */ 665 void ftrace_kill(void); 666 667 static inline void tracer_disable(void) 668 { 669 #ifdef CONFIG_FUNCTION_TRACER 670 ftrace_enabled = 0; 671 #endif 672 } 673 674 /* 675 * Ftrace disable/restore without lock. Some synchronization mechanism 676 * must be used to prevent ftrace_enabled to be changed between 677 * disable/restore. 678 */ 679 static inline int __ftrace_enabled_save(void) 680 { 681 #ifdef CONFIG_FUNCTION_TRACER 682 int saved_ftrace_enabled = ftrace_enabled; 683 ftrace_enabled = 0; 684 return saved_ftrace_enabled; 685 #else 686 return 0; 687 #endif 688 } 689 690 static inline void __ftrace_enabled_restore(int enabled) 691 { 692 #ifdef CONFIG_FUNCTION_TRACER 693 ftrace_enabled = enabled; 694 #endif 695 } 696 697 /* All archs should have this, but we define it for consistency */ 698 #ifndef ftrace_return_address0 699 # define ftrace_return_address0 __builtin_return_address(0) 700 #endif 701 702 /* Archs may use other ways for ADDR1 and beyond */ 703 #ifndef ftrace_return_address 704 # ifdef CONFIG_FRAME_POINTER 705 # define ftrace_return_address(n) __builtin_return_address(n) 706 # else 707 # define ftrace_return_address(n) 0UL 708 # endif 709 #endif 710 711 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 712 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 713 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 714 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 715 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 716 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 717 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 718 719 static inline unsigned long get_lock_parent_ip(void) 720 { 721 unsigned long addr = CALLER_ADDR0; 722 723 if (!in_lock_functions(addr)) 724 return addr; 725 addr = CALLER_ADDR1; 726 if (!in_lock_functions(addr)) 727 return addr; 728 return CALLER_ADDR2; 729 } 730 731 #ifdef CONFIG_IRQSOFF_TRACER 732 extern void time_hardirqs_on(unsigned long a0, unsigned long a1); 733 extern void time_hardirqs_off(unsigned long a0, unsigned long a1); 734 #else 735 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } 736 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } 737 #endif 738 739 #ifdef CONFIG_PREEMPT_TRACER 740 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 741 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 742 #else 743 /* 744 * Use defines instead of static inlines because some arches will make code out 745 * of the CALLER_ADDR, when we really want these to be a real nop. 746 */ 747 # define trace_preempt_on(a0, a1) do { } while (0) 748 # define trace_preempt_off(a0, a1) do { } while (0) 749 #endif 750 751 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 752 extern void ftrace_init(void); 753 #else 754 static inline void ftrace_init(void) { } 755 #endif 756 757 /* 758 * Structure that defines an entry function trace. 759 * It's already packed but the attribute "packed" is needed 760 * to remove extra padding at the end. 761 */ 762 struct ftrace_graph_ent { 763 unsigned long func; /* Current function */ 764 int depth; 765 } __packed; 766 767 /* 768 * Structure that defines a return function trace. 769 * It's already packed but the attribute "packed" is needed 770 * to remove extra padding at the end. 771 */ 772 struct ftrace_graph_ret { 773 unsigned long func; /* Current function */ 774 /* Number of functions that overran the depth limit for current task */ 775 unsigned long overrun; 776 unsigned long long calltime; 777 unsigned long long rettime; 778 int depth; 779 } __packed; 780 781 /* Type of the callback handlers for tracing function graph*/ 782 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 783 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 784 785 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 786 787 /* for init task */ 788 #define INIT_FTRACE_GRAPH .ret_stack = NULL, 789 790 /* 791 * Stack of return addresses for functions 792 * of a thread. 793 * Used in struct thread_info 794 */ 795 struct ftrace_ret_stack { 796 unsigned long ret; 797 unsigned long func; 798 unsigned long long calltime; 799 #ifdef CONFIG_FUNCTION_PROFILER 800 unsigned long long subtime; 801 #endif 802 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 803 unsigned long fp; 804 #endif 805 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 806 unsigned long *retp; 807 #endif 808 }; 809 810 /* 811 * Primary handler of a function return. 812 * It relays on ftrace_return_to_handler. 813 * Defined in entry_32/64.S 814 */ 815 extern void return_to_handler(void); 816 817 extern int 818 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 819 unsigned long frame_pointer, unsigned long *retp); 820 821 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 822 unsigned long ret, unsigned long *retp); 823 824 /* 825 * Sometimes we don't want to trace a function with the function 826 * graph tracer but we want them to keep traced by the usual function 827 * tracer if the function graph tracer is not configured. 828 */ 829 #define __notrace_funcgraph notrace 830 831 #define FTRACE_NOTRACE_DEPTH 65536 832 #define FTRACE_RETFUNC_DEPTH 50 833 #define FTRACE_RETSTACK_ALLOC_SIZE 32 834 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 835 trace_func_graph_ent_t entryfunc); 836 837 extern bool ftrace_graph_is_dead(void); 838 extern void ftrace_graph_stop(void); 839 840 /* The current handlers in use */ 841 extern trace_func_graph_ret_t ftrace_graph_return; 842 extern trace_func_graph_ent_t ftrace_graph_entry; 843 844 extern void unregister_ftrace_graph(void); 845 846 extern void ftrace_graph_init_task(struct task_struct *t); 847 extern void ftrace_graph_exit_task(struct task_struct *t); 848 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 849 850 static inline int task_curr_ret_stack(struct task_struct *t) 851 { 852 return t->curr_ret_stack; 853 } 854 855 static inline void pause_graph_tracing(void) 856 { 857 atomic_inc(¤t->tracing_graph_pause); 858 } 859 860 static inline void unpause_graph_tracing(void) 861 { 862 atomic_dec(¤t->tracing_graph_pause); 863 } 864 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 865 866 #define __notrace_funcgraph 867 #define INIT_FTRACE_GRAPH 868 869 static inline void ftrace_graph_init_task(struct task_struct *t) { } 870 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 871 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 872 873 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 874 trace_func_graph_ent_t entryfunc) 875 { 876 return -1; 877 } 878 static inline void unregister_ftrace_graph(void) { } 879 880 static inline int task_curr_ret_stack(struct task_struct *tsk) 881 { 882 return -1; 883 } 884 885 static inline unsigned long 886 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 887 unsigned long *retp) 888 { 889 return ret; 890 } 891 892 static inline void pause_graph_tracing(void) { } 893 static inline void unpause_graph_tracing(void) { } 894 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 895 896 #ifdef CONFIG_TRACING 897 898 /* flags for current->trace */ 899 enum { 900 TSK_TRACE_FL_TRACE_BIT = 0, 901 TSK_TRACE_FL_GRAPH_BIT = 1, 902 }; 903 enum { 904 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 905 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 906 }; 907 908 static inline void set_tsk_trace_trace(struct task_struct *tsk) 909 { 910 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 911 } 912 913 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 914 { 915 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 916 } 917 918 static inline int test_tsk_trace_trace(struct task_struct *tsk) 919 { 920 return tsk->trace & TSK_TRACE_FL_TRACE; 921 } 922 923 static inline void set_tsk_trace_graph(struct task_struct *tsk) 924 { 925 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 926 } 927 928 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 929 { 930 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 931 } 932 933 static inline int test_tsk_trace_graph(struct task_struct *tsk) 934 { 935 return tsk->trace & TSK_TRACE_FL_GRAPH; 936 } 937 938 enum ftrace_dump_mode; 939 940 extern enum ftrace_dump_mode ftrace_dump_on_oops; 941 extern int tracepoint_printk; 942 943 extern void disable_trace_on_warning(void); 944 extern int __disable_trace_on_warning; 945 946 #ifdef CONFIG_PREEMPT 947 #define INIT_TRACE_RECURSION .trace_recursion = 0, 948 #endif 949 950 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 951 void __user *buffer, size_t *lenp, 952 loff_t *ppos); 953 954 #else /* CONFIG_TRACING */ 955 static inline void disable_trace_on_warning(void) { } 956 #endif /* CONFIG_TRACING */ 957 958 #ifndef INIT_TRACE_RECURSION 959 #define INIT_TRACE_RECURSION 960 #endif 961 962 #ifdef CONFIG_FTRACE_SYSCALLS 963 964 unsigned long arch_syscall_addr(int nr); 965 966 #endif /* CONFIG_FTRACE_SYSCALLS */ 967 968 #endif /* _LINUX_FTRACE_H */ 969