1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Ftrace header. For implementation details beyond the random comments 4 * scattered below, see: Documentation/trace/ftrace-design.txt 5 */ 6 7 #ifndef _LINUX_FTRACE_H 8 #define _LINUX_FTRACE_H 9 10 #include <linux/trace_clock.h> 11 #include <linux/kallsyms.h> 12 #include <linux/linkage.h> 13 #include <linux/bitops.h> 14 #include <linux/ptrace.h> 15 #include <linux/ktime.h> 16 #include <linux/sched.h> 17 #include <linux/types.h> 18 #include <linux/init.h> 19 #include <linux/fs.h> 20 21 #include <asm/ftrace.h> 22 23 /* 24 * If the arch supports passing the variable contents of 25 * function_trace_op as the third parameter back from the 26 * mcount call, then the arch should define this as 1. 27 */ 28 #ifndef ARCH_SUPPORTS_FTRACE_OPS 29 #define ARCH_SUPPORTS_FTRACE_OPS 0 30 #endif 31 32 /* 33 * If the arch's mcount caller does not support all of ftrace's 34 * features, then it must call an indirect function that 35 * does. Or at least does enough to prevent any unwelcomed side effects. 36 */ 37 #if !ARCH_SUPPORTS_FTRACE_OPS 38 # define FTRACE_FORCE_LIST_FUNC 1 39 #else 40 # define FTRACE_FORCE_LIST_FUNC 0 41 #endif 42 43 /* Main tracing buffer and events set up */ 44 #ifdef CONFIG_TRACING 45 void trace_init(void); 46 void early_trace_init(void); 47 #else 48 static inline void trace_init(void) { } 49 static inline void early_trace_init(void) { } 50 #endif 51 52 struct module; 53 struct ftrace_hash; 54 55 #ifdef CONFIG_FUNCTION_TRACER 56 57 extern int ftrace_enabled; 58 extern int 59 ftrace_enable_sysctl(struct ctl_table *table, int write, 60 void __user *buffer, size_t *lenp, 61 loff_t *ppos); 62 63 struct ftrace_ops; 64 65 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 66 struct ftrace_ops *op, struct pt_regs *regs); 67 68 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 69 70 /* 71 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 72 * set in the flags member. 73 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION_SAFE, STUB and 74 * IPMODIFY are a kind of attribute flags which can be set only before 75 * registering the ftrace_ops, and can not be modified while registered. 76 * Changing those attribute flags after registering ftrace_ops will 77 * cause unexpected results. 78 * 79 * ENABLED - set/unset when ftrace_ops is registered/unregistered 80 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 81 * allocated ftrace_ops which need special care 82 * PER_CPU - set manualy by ftrace_ops user to denote the ftrace_ops 83 * could be controlled by following calls: 84 * ftrace_function_local_enable 85 * ftrace_function_local_disable 86 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 87 * and passed to the callback. If this flag is set, but the 88 * architecture does not support passing regs 89 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 90 * ftrace_ops will fail to register, unless the next flag 91 * is set. 92 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 93 * handler can handle an arch that does not save regs 94 * (the handler tests if regs == NULL), then it can set 95 * this flag instead. It will not fail registering the ftrace_ops 96 * but, the regs field will be NULL if the arch does not support 97 * passing regs to the handler. 98 * Note, if this flag is set, the SAVE_REGS flag will automatically 99 * get set upon registering the ftrace_ops, if the arch supports it. 100 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure 101 * that the call back has its own recursion protection. If it does 102 * not set this, then the ftrace infrastructure will add recursion 103 * protection for the caller. 104 * STUB - The ftrace_ops is just a place holder. 105 * INITIALIZED - The ftrace_ops has already been initialized (first use time 106 * register_ftrace_function() is called, it will initialized the ops) 107 * DELETED - The ops are being deleted, do not let them be registered again. 108 * ADDING - The ops is in the process of being added. 109 * REMOVING - The ops is in the process of being removed. 110 * MODIFYING - The ops is in the process of changing its filter functions. 111 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 112 * The arch specific code sets this flag when it allocated a 113 * trampoline. This lets the arch know that it can update the 114 * trampoline in case the callback function changes. 115 * The ftrace_ops trampoline can be set by the ftrace users, and 116 * in such cases the arch must not modify it. Only the arch ftrace 117 * core code should set this flag. 118 * IPMODIFY - The ops can modify the IP register. This can only be set with 119 * SAVE_REGS. If another ops with this flag set is already registered 120 * for any of the functions that this ops will be registered for, then 121 * this ops will fail to register or set_filter_ip. 122 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 123 * RCU - Set when the ops can only be called when RCU is watching. 124 * TRACE_ARRAY - The ops->private points to a trace_array descriptor. 125 */ 126 enum { 127 FTRACE_OPS_FL_ENABLED = 1 << 0, 128 FTRACE_OPS_FL_DYNAMIC = 1 << 1, 129 FTRACE_OPS_FL_PER_CPU = 1 << 2, 130 FTRACE_OPS_FL_SAVE_REGS = 1 << 3, 131 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 4, 132 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 5, 133 FTRACE_OPS_FL_STUB = 1 << 6, 134 FTRACE_OPS_FL_INITIALIZED = 1 << 7, 135 FTRACE_OPS_FL_DELETED = 1 << 8, 136 FTRACE_OPS_FL_ADDING = 1 << 9, 137 FTRACE_OPS_FL_REMOVING = 1 << 10, 138 FTRACE_OPS_FL_MODIFYING = 1 << 11, 139 FTRACE_OPS_FL_ALLOC_TRAMP = 1 << 12, 140 FTRACE_OPS_FL_IPMODIFY = 1 << 13, 141 FTRACE_OPS_FL_PID = 1 << 14, 142 FTRACE_OPS_FL_RCU = 1 << 15, 143 FTRACE_OPS_FL_TRACE_ARRAY = 1 << 16, 144 }; 145 146 #ifdef CONFIG_DYNAMIC_FTRACE 147 /* The hash used to know what functions callbacks trace */ 148 struct ftrace_ops_hash { 149 struct ftrace_hash __rcu *notrace_hash; 150 struct ftrace_hash __rcu *filter_hash; 151 struct mutex regex_lock; 152 }; 153 154 void ftrace_free_init_mem(void); 155 #else 156 static inline void ftrace_free_init_mem(void) { } 157 #endif 158 159 /* 160 * Note, ftrace_ops can be referenced outside of RCU protection, unless 161 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel 162 * core data, the unregistering of it will perform a scheduling on all CPUs 163 * to make sure that there are no more users. Depending on the load of the 164 * system that may take a bit of time. 165 * 166 * Any private data added must also take care not to be freed and if private 167 * data is added to a ftrace_ops that is in core code, the user of the 168 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 169 */ 170 struct ftrace_ops { 171 ftrace_func_t func; 172 struct ftrace_ops __rcu *next; 173 unsigned long flags; 174 void *private; 175 ftrace_func_t saved_func; 176 int __percpu *disabled; 177 #ifdef CONFIG_DYNAMIC_FTRACE 178 struct ftrace_ops_hash local_hash; 179 struct ftrace_ops_hash *func_hash; 180 struct ftrace_ops_hash old_hash; 181 unsigned long trampoline; 182 unsigned long trampoline_size; 183 #endif 184 }; 185 186 /* 187 * Type of the current tracing. 188 */ 189 enum ftrace_tracing_type_t { 190 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 191 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 192 }; 193 194 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 195 extern enum ftrace_tracing_type_t ftrace_tracing_type; 196 197 /* 198 * The ftrace_ops must be a static and should also 199 * be read_mostly. These functions do modify read_mostly variables 200 * so use them sparely. Never free an ftrace_op or modify the 201 * next pointer after it has been registered. Even after unregistering 202 * it, the next pointer may still be used internally. 203 */ 204 int register_ftrace_function(struct ftrace_ops *ops); 205 int unregister_ftrace_function(struct ftrace_ops *ops); 206 void clear_ftrace_function(void); 207 208 /** 209 * ftrace_function_local_enable - enable ftrace_ops on current cpu 210 * 211 * This function enables tracing on current cpu by decreasing 212 * the per cpu control variable. 213 * It must be called with preemption disabled and only on ftrace_ops 214 * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption 215 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 216 */ 217 static inline void ftrace_function_local_enable(struct ftrace_ops *ops) 218 { 219 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU))) 220 return; 221 222 (*this_cpu_ptr(ops->disabled))--; 223 } 224 225 /** 226 * ftrace_function_local_disable - disable ftrace_ops on current cpu 227 * 228 * This function disables tracing on current cpu by increasing 229 * the per cpu control variable. 230 * It must be called with preemption disabled and only on ftrace_ops 231 * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption 232 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 233 */ 234 static inline void ftrace_function_local_disable(struct ftrace_ops *ops) 235 { 236 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU))) 237 return; 238 239 (*this_cpu_ptr(ops->disabled))++; 240 } 241 242 /** 243 * ftrace_function_local_disabled - returns ftrace_ops disabled value 244 * on current cpu 245 * 246 * This function returns value of ftrace_ops::disabled on current cpu. 247 * It must be called with preemption disabled and only on ftrace_ops 248 * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption 249 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. 250 */ 251 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) 252 { 253 WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)); 254 return *this_cpu_ptr(ops->disabled); 255 } 256 257 extern void ftrace_stub(unsigned long a0, unsigned long a1, 258 struct ftrace_ops *op, struct pt_regs *regs); 259 260 #else /* !CONFIG_FUNCTION_TRACER */ 261 /* 262 * (un)register_ftrace_function must be a macro since the ops parameter 263 * must not be evaluated. 264 */ 265 #define register_ftrace_function(ops) ({ 0; }) 266 #define unregister_ftrace_function(ops) ({ 0; }) 267 static inline int ftrace_nr_registered_ops(void) 268 { 269 return 0; 270 } 271 static inline void clear_ftrace_function(void) { } 272 static inline void ftrace_kill(void) { } 273 static inline void ftrace_free_init_mem(void) { } 274 #endif /* CONFIG_FUNCTION_TRACER */ 275 276 #ifdef CONFIG_STACK_TRACER 277 278 #define STACK_TRACE_ENTRIES 500 279 280 struct stack_trace; 281 282 extern unsigned stack_trace_index[]; 283 extern struct stack_trace stack_trace_max; 284 extern unsigned long stack_trace_max_size; 285 extern arch_spinlock_t stack_trace_max_lock; 286 287 extern int stack_tracer_enabled; 288 void stack_trace_print(void); 289 int 290 stack_trace_sysctl(struct ctl_table *table, int write, 291 void __user *buffer, size_t *lenp, 292 loff_t *ppos); 293 294 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 295 DECLARE_PER_CPU(int, disable_stack_tracer); 296 297 /** 298 * stack_tracer_disable - temporarily disable the stack tracer 299 * 300 * There's a few locations (namely in RCU) where stack tracing 301 * cannot be executed. This function is used to disable stack 302 * tracing during those critical sections. 303 * 304 * This function must be called with preemption or interrupts 305 * disabled and stack_tracer_enable() must be called shortly after 306 * while preemption or interrupts are still disabled. 307 */ 308 static inline void stack_tracer_disable(void) 309 { 310 /* Preemption or interupts must be disabled */ 311 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 312 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 313 this_cpu_inc(disable_stack_tracer); 314 } 315 316 /** 317 * stack_tracer_enable - re-enable the stack tracer 318 * 319 * After stack_tracer_disable() is called, stack_tracer_enable() 320 * must be called shortly afterward. 321 */ 322 static inline void stack_tracer_enable(void) 323 { 324 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 325 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 326 this_cpu_dec(disable_stack_tracer); 327 } 328 #else 329 static inline void stack_tracer_disable(void) { } 330 static inline void stack_tracer_enable(void) { } 331 #endif 332 333 #ifdef CONFIG_DYNAMIC_FTRACE 334 335 int ftrace_arch_code_modify_prepare(void); 336 int ftrace_arch_code_modify_post_process(void); 337 338 struct dyn_ftrace; 339 340 enum ftrace_bug_type { 341 FTRACE_BUG_UNKNOWN, 342 FTRACE_BUG_INIT, 343 FTRACE_BUG_NOP, 344 FTRACE_BUG_CALL, 345 FTRACE_BUG_UPDATE, 346 }; 347 extern enum ftrace_bug_type ftrace_bug_type; 348 349 /* 350 * Archs can set this to point to a variable that holds the value that was 351 * expected at the call site before calling ftrace_bug(). 352 */ 353 extern const void *ftrace_expected; 354 355 void ftrace_bug(int err, struct dyn_ftrace *rec); 356 357 struct seq_file; 358 359 extern int ftrace_text_reserved(const void *start, const void *end); 360 361 extern int ftrace_nr_registered_ops(void); 362 363 bool is_ftrace_trampoline(unsigned long addr); 364 365 /* 366 * The dyn_ftrace record's flags field is split into two parts. 367 * the first part which is '0-FTRACE_REF_MAX' is a counter of 368 * the number of callbacks that have registered the function that 369 * the dyn_ftrace descriptor represents. 370 * 371 * The second part is a mask: 372 * ENABLED - the function is being traced 373 * REGS - the record wants the function to save regs 374 * REGS_EN - the function is set up to save regs. 375 * IPMODIFY - the record allows for the IP address to be changed. 376 * DISABLED - the record is not ready to be touched yet 377 * 378 * When a new ftrace_ops is registered and wants a function to save 379 * pt_regs, the rec->flag REGS is set. When the function has been 380 * set up to save regs, the REG_EN flag is set. Once a function 381 * starts saving regs it will do so until all ftrace_ops are removed 382 * from tracing that function. 383 */ 384 enum { 385 FTRACE_FL_ENABLED = (1UL << 31), 386 FTRACE_FL_REGS = (1UL << 30), 387 FTRACE_FL_REGS_EN = (1UL << 29), 388 FTRACE_FL_TRAMP = (1UL << 28), 389 FTRACE_FL_TRAMP_EN = (1UL << 27), 390 FTRACE_FL_IPMODIFY = (1UL << 26), 391 FTRACE_FL_DISABLED = (1UL << 25), 392 }; 393 394 #define FTRACE_REF_MAX_SHIFT 25 395 #define FTRACE_FL_BITS 7 396 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 397 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 398 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 399 400 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 401 402 struct dyn_ftrace { 403 unsigned long ip; /* address of mcount call-site */ 404 unsigned long flags; 405 struct dyn_arch_ftrace arch; 406 }; 407 408 int ftrace_force_update(void); 409 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 410 int remove, int reset); 411 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 412 int len, int reset); 413 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 414 int len, int reset); 415 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 416 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 417 void ftrace_free_filter(struct ftrace_ops *ops); 418 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 419 420 enum { 421 FTRACE_UPDATE_CALLS = (1 << 0), 422 FTRACE_DISABLE_CALLS = (1 << 1), 423 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 424 FTRACE_START_FUNC_RET = (1 << 3), 425 FTRACE_STOP_FUNC_RET = (1 << 4), 426 }; 427 428 /* 429 * The FTRACE_UPDATE_* enum is used to pass information back 430 * from the ftrace_update_record() and ftrace_test_record() 431 * functions. These are called by the code update routines 432 * to find out what is to be done for a given function. 433 * 434 * IGNORE - The function is already what we want it to be 435 * MAKE_CALL - Start tracing the function 436 * MODIFY_CALL - Stop saving regs for the function 437 * MAKE_NOP - Stop tracing the function 438 */ 439 enum { 440 FTRACE_UPDATE_IGNORE, 441 FTRACE_UPDATE_MAKE_CALL, 442 FTRACE_UPDATE_MODIFY_CALL, 443 FTRACE_UPDATE_MAKE_NOP, 444 }; 445 446 enum { 447 FTRACE_ITER_FILTER = (1 << 0), 448 FTRACE_ITER_NOTRACE = (1 << 1), 449 FTRACE_ITER_PRINTALL = (1 << 2), 450 FTRACE_ITER_DO_PROBES = (1 << 3), 451 FTRACE_ITER_PROBE = (1 << 4), 452 FTRACE_ITER_MOD = (1 << 5), 453 FTRACE_ITER_ENABLED = (1 << 6), 454 }; 455 456 void arch_ftrace_update_code(int command); 457 458 struct ftrace_rec_iter; 459 460 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 461 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 462 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 463 464 #define for_ftrace_rec_iter(iter) \ 465 for (iter = ftrace_rec_iter_start(); \ 466 iter; \ 467 iter = ftrace_rec_iter_next(iter)) 468 469 470 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 471 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 472 void ftrace_run_stop_machine(int command); 473 unsigned long ftrace_location(unsigned long ip); 474 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 475 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 476 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 477 478 extern ftrace_func_t ftrace_trace_function; 479 480 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 481 struct inode *inode, struct file *file); 482 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 483 size_t cnt, loff_t *ppos); 484 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 485 size_t cnt, loff_t *ppos); 486 int ftrace_regex_release(struct inode *inode, struct file *file); 487 488 void __init 489 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 490 491 /* defined in arch */ 492 extern int ftrace_ip_converted(unsigned long ip); 493 extern int ftrace_dyn_arch_init(void); 494 extern void ftrace_replace_code(int enable); 495 extern int ftrace_update_ftrace_func(ftrace_func_t func); 496 extern void ftrace_caller(void); 497 extern void ftrace_regs_caller(void); 498 extern void ftrace_call(void); 499 extern void ftrace_regs_call(void); 500 extern void mcount_call(void); 501 502 void ftrace_modify_all_code(int command); 503 504 #ifndef FTRACE_ADDR 505 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 506 #endif 507 508 #ifndef FTRACE_GRAPH_ADDR 509 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 510 #endif 511 512 #ifndef FTRACE_REGS_ADDR 513 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 514 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 515 #else 516 # define FTRACE_REGS_ADDR FTRACE_ADDR 517 #endif 518 #endif 519 520 /* 521 * If an arch would like functions that are only traced 522 * by the function graph tracer to jump directly to its own 523 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 524 * to be that address to jump to. 525 */ 526 #ifndef FTRACE_GRAPH_TRAMP_ADDR 527 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 528 #endif 529 530 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 531 extern void ftrace_graph_caller(void); 532 extern int ftrace_enable_ftrace_graph_caller(void); 533 extern int ftrace_disable_ftrace_graph_caller(void); 534 #else 535 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 536 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 537 #endif 538 539 /** 540 * ftrace_make_nop - convert code into nop 541 * @mod: module structure if called by module load initialization 542 * @rec: the mcount call site record 543 * @addr: the address that the call site should be calling 544 * 545 * This is a very sensitive operation and great care needs 546 * to be taken by the arch. The operation should carefully 547 * read the location, check to see if what is read is indeed 548 * what we expect it to be, and then on success of the compare, 549 * it should write to the location. 550 * 551 * The code segment at @rec->ip should be a caller to @addr 552 * 553 * Return must be: 554 * 0 on success 555 * -EFAULT on error reading the location 556 * -EINVAL on a failed compare of the contents 557 * -EPERM on error writing to the location 558 * Any other value will be considered a failure. 559 */ 560 extern int ftrace_make_nop(struct module *mod, 561 struct dyn_ftrace *rec, unsigned long addr); 562 563 /** 564 * ftrace_make_call - convert a nop call site into a call to addr 565 * @rec: the mcount call site record 566 * @addr: the address that the call site should call 567 * 568 * This is a very sensitive operation and great care needs 569 * to be taken by the arch. The operation should carefully 570 * read the location, check to see if what is read is indeed 571 * what we expect it to be, and then on success of the compare, 572 * it should write to the location. 573 * 574 * The code segment at @rec->ip should be a nop 575 * 576 * Return must be: 577 * 0 on success 578 * -EFAULT on error reading the location 579 * -EINVAL on a failed compare of the contents 580 * -EPERM on error writing to the location 581 * Any other value will be considered a failure. 582 */ 583 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 584 585 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 586 /** 587 * ftrace_modify_call - convert from one addr to another (no nop) 588 * @rec: the mcount call site record 589 * @old_addr: the address expected to be currently called to 590 * @addr: the address to change to 591 * 592 * This is a very sensitive operation and great care needs 593 * to be taken by the arch. The operation should carefully 594 * read the location, check to see if what is read is indeed 595 * what we expect it to be, and then on success of the compare, 596 * it should write to the location. 597 * 598 * The code segment at @rec->ip should be a caller to @old_addr 599 * 600 * Return must be: 601 * 0 on success 602 * -EFAULT on error reading the location 603 * -EINVAL on a failed compare of the contents 604 * -EPERM on error writing to the location 605 * Any other value will be considered a failure. 606 */ 607 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 608 unsigned long addr); 609 #else 610 /* Should never be called */ 611 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 612 unsigned long addr) 613 { 614 return -EINVAL; 615 } 616 #endif 617 618 /* May be defined in arch */ 619 extern int ftrace_arch_read_dyn_info(char *buf, int size); 620 621 extern int skip_trace(unsigned long ip); 622 extern void ftrace_module_init(struct module *mod); 623 extern void ftrace_module_enable(struct module *mod); 624 extern void ftrace_release_mod(struct module *mod); 625 626 extern void ftrace_disable_daemon(void); 627 extern void ftrace_enable_daemon(void); 628 #else /* CONFIG_DYNAMIC_FTRACE */ 629 static inline int skip_trace(unsigned long ip) { return 0; } 630 static inline int ftrace_force_update(void) { return 0; } 631 static inline void ftrace_disable_daemon(void) { } 632 static inline void ftrace_enable_daemon(void) { } 633 static inline void ftrace_module_init(struct module *mod) { } 634 static inline void ftrace_module_enable(struct module *mod) { } 635 static inline void ftrace_release_mod(struct module *mod) { } 636 static inline int ftrace_text_reserved(const void *start, const void *end) 637 { 638 return 0; 639 } 640 static inline unsigned long ftrace_location(unsigned long ip) 641 { 642 return 0; 643 } 644 645 /* 646 * Again users of functions that have ftrace_ops may not 647 * have them defined when ftrace is not enabled, but these 648 * functions may still be called. Use a macro instead of inline. 649 */ 650 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 651 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 652 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 653 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 654 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 655 #define ftrace_free_filter(ops) do { } while (0) 656 #define ftrace_ops_set_global_filter(ops) do { } while (0) 657 658 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 659 size_t cnt, loff_t *ppos) { return -ENODEV; } 660 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 661 size_t cnt, loff_t *ppos) { return -ENODEV; } 662 static inline int 663 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 664 665 static inline bool is_ftrace_trampoline(unsigned long addr) 666 { 667 return false; 668 } 669 #endif /* CONFIG_DYNAMIC_FTRACE */ 670 671 /* totally disable ftrace - can not re-enable after this */ 672 void ftrace_kill(void); 673 674 static inline void tracer_disable(void) 675 { 676 #ifdef CONFIG_FUNCTION_TRACER 677 ftrace_enabled = 0; 678 #endif 679 } 680 681 /* 682 * Ftrace disable/restore without lock. Some synchronization mechanism 683 * must be used to prevent ftrace_enabled to be changed between 684 * disable/restore. 685 */ 686 static inline int __ftrace_enabled_save(void) 687 { 688 #ifdef CONFIG_FUNCTION_TRACER 689 int saved_ftrace_enabled = ftrace_enabled; 690 ftrace_enabled = 0; 691 return saved_ftrace_enabled; 692 #else 693 return 0; 694 #endif 695 } 696 697 static inline void __ftrace_enabled_restore(int enabled) 698 { 699 #ifdef CONFIG_FUNCTION_TRACER 700 ftrace_enabled = enabled; 701 #endif 702 } 703 704 /* All archs should have this, but we define it for consistency */ 705 #ifndef ftrace_return_address0 706 # define ftrace_return_address0 __builtin_return_address(0) 707 #endif 708 709 /* Archs may use other ways for ADDR1 and beyond */ 710 #ifndef ftrace_return_address 711 # ifdef CONFIG_FRAME_POINTER 712 # define ftrace_return_address(n) __builtin_return_address(n) 713 # else 714 # define ftrace_return_address(n) 0UL 715 # endif 716 #endif 717 718 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 719 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 720 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 721 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 722 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 723 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 724 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 725 726 static inline unsigned long get_lock_parent_ip(void) 727 { 728 unsigned long addr = CALLER_ADDR0; 729 730 if (!in_lock_functions(addr)) 731 return addr; 732 addr = CALLER_ADDR1; 733 if (!in_lock_functions(addr)) 734 return addr; 735 return CALLER_ADDR2; 736 } 737 738 #ifdef CONFIG_IRQSOFF_TRACER 739 extern void time_hardirqs_on(unsigned long a0, unsigned long a1); 740 extern void time_hardirqs_off(unsigned long a0, unsigned long a1); 741 #else 742 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } 743 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } 744 #endif 745 746 #ifdef CONFIG_PREEMPT_TRACER 747 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 748 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 749 #else 750 /* 751 * Use defines instead of static inlines because some arches will make code out 752 * of the CALLER_ADDR, when we really want these to be a real nop. 753 */ 754 # define trace_preempt_on(a0, a1) do { } while (0) 755 # define trace_preempt_off(a0, a1) do { } while (0) 756 #endif 757 758 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 759 extern void ftrace_init(void); 760 #else 761 static inline void ftrace_init(void) { } 762 #endif 763 764 /* 765 * Structure that defines an entry function trace. 766 * It's already packed but the attribute "packed" is needed 767 * to remove extra padding at the end. 768 */ 769 struct ftrace_graph_ent { 770 unsigned long func; /* Current function */ 771 int depth; 772 } __packed; 773 774 /* 775 * Structure that defines a return function trace. 776 * It's already packed but the attribute "packed" is needed 777 * to remove extra padding at the end. 778 */ 779 struct ftrace_graph_ret { 780 unsigned long func; /* Current function */ 781 /* Number of functions that overran the depth limit for current task */ 782 unsigned long overrun; 783 unsigned long long calltime; 784 unsigned long long rettime; 785 int depth; 786 } __packed; 787 788 /* Type of the callback handlers for tracing function graph*/ 789 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 790 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 791 792 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 793 794 /* for init task */ 795 #define INIT_FTRACE_GRAPH .ret_stack = NULL, 796 797 /* 798 * Stack of return addresses for functions 799 * of a thread. 800 * Used in struct thread_info 801 */ 802 struct ftrace_ret_stack { 803 unsigned long ret; 804 unsigned long func; 805 unsigned long long calltime; 806 #ifdef CONFIG_FUNCTION_PROFILER 807 unsigned long long subtime; 808 #endif 809 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 810 unsigned long fp; 811 #endif 812 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 813 unsigned long *retp; 814 #endif 815 }; 816 817 /* 818 * Primary handler of a function return. 819 * It relays on ftrace_return_to_handler. 820 * Defined in entry_32/64.S 821 */ 822 extern void return_to_handler(void); 823 824 extern int 825 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 826 unsigned long frame_pointer, unsigned long *retp); 827 828 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 829 unsigned long ret, unsigned long *retp); 830 831 /* 832 * Sometimes we don't want to trace a function with the function 833 * graph tracer but we want them to keep traced by the usual function 834 * tracer if the function graph tracer is not configured. 835 */ 836 #define __notrace_funcgraph notrace 837 838 #define FTRACE_NOTRACE_DEPTH 65536 839 #define FTRACE_RETFUNC_DEPTH 50 840 #define FTRACE_RETSTACK_ALLOC_SIZE 32 841 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 842 trace_func_graph_ent_t entryfunc); 843 844 extern bool ftrace_graph_is_dead(void); 845 extern void ftrace_graph_stop(void); 846 847 /* The current handlers in use */ 848 extern trace_func_graph_ret_t ftrace_graph_return; 849 extern trace_func_graph_ent_t ftrace_graph_entry; 850 851 extern void unregister_ftrace_graph(void); 852 853 extern void ftrace_graph_init_task(struct task_struct *t); 854 extern void ftrace_graph_exit_task(struct task_struct *t); 855 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 856 857 static inline int task_curr_ret_stack(struct task_struct *t) 858 { 859 return t->curr_ret_stack; 860 } 861 862 static inline void pause_graph_tracing(void) 863 { 864 atomic_inc(¤t->tracing_graph_pause); 865 } 866 867 static inline void unpause_graph_tracing(void) 868 { 869 atomic_dec(¤t->tracing_graph_pause); 870 } 871 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 872 873 #define __notrace_funcgraph 874 #define INIT_FTRACE_GRAPH 875 876 static inline void ftrace_graph_init_task(struct task_struct *t) { } 877 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 878 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 879 880 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 881 trace_func_graph_ent_t entryfunc) 882 { 883 return -1; 884 } 885 static inline void unregister_ftrace_graph(void) { } 886 887 static inline int task_curr_ret_stack(struct task_struct *tsk) 888 { 889 return -1; 890 } 891 892 static inline unsigned long 893 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 894 unsigned long *retp) 895 { 896 return ret; 897 } 898 899 static inline void pause_graph_tracing(void) { } 900 static inline void unpause_graph_tracing(void) { } 901 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 902 903 #ifdef CONFIG_TRACING 904 905 /* flags for current->trace */ 906 enum { 907 TSK_TRACE_FL_TRACE_BIT = 0, 908 TSK_TRACE_FL_GRAPH_BIT = 1, 909 }; 910 enum { 911 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 912 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 913 }; 914 915 static inline void set_tsk_trace_trace(struct task_struct *tsk) 916 { 917 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 918 } 919 920 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 921 { 922 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 923 } 924 925 static inline int test_tsk_trace_trace(struct task_struct *tsk) 926 { 927 return tsk->trace & TSK_TRACE_FL_TRACE; 928 } 929 930 static inline void set_tsk_trace_graph(struct task_struct *tsk) 931 { 932 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 933 } 934 935 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 936 { 937 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 938 } 939 940 static inline int test_tsk_trace_graph(struct task_struct *tsk) 941 { 942 return tsk->trace & TSK_TRACE_FL_GRAPH; 943 } 944 945 enum ftrace_dump_mode; 946 947 extern enum ftrace_dump_mode ftrace_dump_on_oops; 948 extern int tracepoint_printk; 949 950 extern void disable_trace_on_warning(void); 951 extern int __disable_trace_on_warning; 952 953 #ifdef CONFIG_PREEMPT 954 #define INIT_TRACE_RECURSION .trace_recursion = 0, 955 #endif 956 957 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 958 void __user *buffer, size_t *lenp, 959 loff_t *ppos); 960 961 #else /* CONFIG_TRACING */ 962 static inline void disable_trace_on_warning(void) { } 963 #endif /* CONFIG_TRACING */ 964 965 #ifndef INIT_TRACE_RECURSION 966 #define INIT_TRACE_RECURSION 967 #endif 968 969 #ifdef CONFIG_FTRACE_SYSCALLS 970 971 unsigned long arch_syscall_addr(int nr); 972 973 #endif /* CONFIG_FTRACE_SYSCALLS */ 974 975 #endif /* _LINUX_FTRACE_H */ 976