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.rst 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 struct ftrace_direct_func; 55 56 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \ 57 defined(CONFIG_DYNAMIC_FTRACE) 58 const char * 59 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 60 unsigned long *off, char **modname, char *sym); 61 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 62 char *type, char *name, 63 char *module_name, int *exported); 64 #else 65 static inline const char * 66 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 67 unsigned long *off, char **modname, char *sym) 68 { 69 return NULL; 70 } 71 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 72 char *type, char *name, 73 char *module_name, int *exported) 74 { 75 return -1; 76 } 77 #endif 78 79 80 #ifdef CONFIG_FUNCTION_TRACER 81 82 extern int ftrace_enabled; 83 extern int 84 ftrace_enable_sysctl(struct ctl_table *table, int write, 85 void __user *buffer, size_t *lenp, 86 loff_t *ppos); 87 88 struct ftrace_ops; 89 90 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 91 struct ftrace_ops *op, struct pt_regs *regs); 92 93 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 94 95 /* 96 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 97 * set in the flags member. 98 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION_SAFE, STUB and 99 * IPMODIFY are a kind of attribute flags which can be set only before 100 * registering the ftrace_ops, and can not be modified while registered. 101 * Changing those attribute flags after registering ftrace_ops will 102 * cause unexpected results. 103 * 104 * ENABLED - set/unset when ftrace_ops is registered/unregistered 105 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 106 * allocated ftrace_ops which need special care 107 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 108 * and passed to the callback. If this flag is set, but the 109 * architecture does not support passing regs 110 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 111 * ftrace_ops will fail to register, unless the next flag 112 * is set. 113 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 114 * handler can handle an arch that does not save regs 115 * (the handler tests if regs == NULL), then it can set 116 * this flag instead. It will not fail registering the ftrace_ops 117 * but, the regs field will be NULL if the arch does not support 118 * passing regs to the handler. 119 * Note, if this flag is set, the SAVE_REGS flag will automatically 120 * get set upon registering the ftrace_ops, if the arch supports it. 121 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure 122 * that the call back has its own recursion protection. If it does 123 * not set this, then the ftrace infrastructure will add recursion 124 * protection for the caller. 125 * STUB - The ftrace_ops is just a place holder. 126 * INITIALIZED - The ftrace_ops has already been initialized (first use time 127 * register_ftrace_function() is called, it will initialized the ops) 128 * DELETED - The ops are being deleted, do not let them be registered again. 129 * ADDING - The ops is in the process of being added. 130 * REMOVING - The ops is in the process of being removed. 131 * MODIFYING - The ops is in the process of changing its filter functions. 132 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 133 * The arch specific code sets this flag when it allocated a 134 * trampoline. This lets the arch know that it can update the 135 * trampoline in case the callback function changes. 136 * The ftrace_ops trampoline can be set by the ftrace users, and 137 * in such cases the arch must not modify it. Only the arch ftrace 138 * core code should set this flag. 139 * IPMODIFY - The ops can modify the IP register. This can only be set with 140 * SAVE_REGS. If another ops with this flag set is already registered 141 * for any of the functions that this ops will be registered for, then 142 * this ops will fail to register or set_filter_ip. 143 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 144 * RCU - Set when the ops can only be called when RCU is watching. 145 * TRACE_ARRAY - The ops->private points to a trace_array descriptor. 146 * PERMANENT - Set when the ops is permanent and should not be affected by 147 * ftrace_enabled. 148 * DIRECT - Used by the direct ftrace_ops helper for direct functions 149 * (internal ftrace only, should not be used by others) 150 */ 151 enum { 152 FTRACE_OPS_FL_ENABLED = BIT(0), 153 FTRACE_OPS_FL_DYNAMIC = BIT(1), 154 FTRACE_OPS_FL_SAVE_REGS = BIT(2), 155 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3), 156 FTRACE_OPS_FL_RECURSION_SAFE = BIT(4), 157 FTRACE_OPS_FL_STUB = BIT(5), 158 FTRACE_OPS_FL_INITIALIZED = BIT(6), 159 FTRACE_OPS_FL_DELETED = BIT(7), 160 FTRACE_OPS_FL_ADDING = BIT(8), 161 FTRACE_OPS_FL_REMOVING = BIT(9), 162 FTRACE_OPS_FL_MODIFYING = BIT(10), 163 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11), 164 FTRACE_OPS_FL_IPMODIFY = BIT(12), 165 FTRACE_OPS_FL_PID = BIT(13), 166 FTRACE_OPS_FL_RCU = BIT(14), 167 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15), 168 FTRACE_OPS_FL_PERMANENT = BIT(16), 169 FTRACE_OPS_FL_DIRECT = BIT(17), 170 }; 171 172 #ifdef CONFIG_DYNAMIC_FTRACE 173 /* The hash used to know what functions callbacks trace */ 174 struct ftrace_ops_hash { 175 struct ftrace_hash __rcu *notrace_hash; 176 struct ftrace_hash __rcu *filter_hash; 177 struct mutex regex_lock; 178 }; 179 180 void ftrace_free_init_mem(void); 181 void ftrace_free_mem(struct module *mod, void *start, void *end); 182 #else 183 static inline void ftrace_free_init_mem(void) { } 184 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 185 #endif 186 187 /* 188 * Note, ftrace_ops can be referenced outside of RCU protection, unless 189 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel 190 * core data, the unregistering of it will perform a scheduling on all CPUs 191 * to make sure that there are no more users. Depending on the load of the 192 * system that may take a bit of time. 193 * 194 * Any private data added must also take care not to be freed and if private 195 * data is added to a ftrace_ops that is in core code, the user of the 196 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 197 */ 198 struct ftrace_ops { 199 ftrace_func_t func; 200 struct ftrace_ops __rcu *next; 201 unsigned long flags; 202 void *private; 203 ftrace_func_t saved_func; 204 #ifdef CONFIG_DYNAMIC_FTRACE 205 struct ftrace_ops_hash local_hash; 206 struct ftrace_ops_hash *func_hash; 207 struct ftrace_ops_hash old_hash; 208 unsigned long trampoline; 209 unsigned long trampoline_size; 210 #endif 211 }; 212 213 /* 214 * Type of the current tracing. 215 */ 216 enum ftrace_tracing_type_t { 217 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 218 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 219 }; 220 221 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 222 extern enum ftrace_tracing_type_t ftrace_tracing_type; 223 224 /* 225 * The ftrace_ops must be a static and should also 226 * be read_mostly. These functions do modify read_mostly variables 227 * so use them sparely. Never free an ftrace_op or modify the 228 * next pointer after it has been registered. Even after unregistering 229 * it, the next pointer may still be used internally. 230 */ 231 int register_ftrace_function(struct ftrace_ops *ops); 232 int unregister_ftrace_function(struct ftrace_ops *ops); 233 234 extern void ftrace_stub(unsigned long a0, unsigned long a1, 235 struct ftrace_ops *op, struct pt_regs *regs); 236 237 #else /* !CONFIG_FUNCTION_TRACER */ 238 /* 239 * (un)register_ftrace_function must be a macro since the ops parameter 240 * must not be evaluated. 241 */ 242 #define register_ftrace_function(ops) ({ 0; }) 243 #define unregister_ftrace_function(ops) ({ 0; }) 244 static inline void ftrace_kill(void) { } 245 static inline void ftrace_free_init_mem(void) { } 246 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 247 #endif /* CONFIG_FUNCTION_TRACER */ 248 249 struct ftrace_func_entry { 250 struct hlist_node hlist; 251 unsigned long ip; 252 unsigned long direct; /* for direct lookup only */ 253 }; 254 255 struct dyn_ftrace; 256 257 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 258 extern int ftrace_direct_func_count; 259 int register_ftrace_direct(unsigned long ip, unsigned long addr); 260 int unregister_ftrace_direct(unsigned long ip, unsigned long addr); 261 int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr); 262 struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr); 263 int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 264 struct dyn_ftrace *rec, 265 unsigned long old_addr, 266 unsigned long new_addr); 267 unsigned long ftrace_find_rec_direct(unsigned long ip); 268 #else 269 # define ftrace_direct_func_count 0 270 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr) 271 { 272 return -ENOTSUPP; 273 } 274 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr) 275 { 276 return -ENOTSUPP; 277 } 278 static inline int modify_ftrace_direct(unsigned long ip, 279 unsigned long old_addr, unsigned long new_addr) 280 { 281 return -ENOTSUPP; 282 } 283 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) 284 { 285 return NULL; 286 } 287 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 288 struct dyn_ftrace *rec, 289 unsigned long old_addr, 290 unsigned long new_addr) 291 { 292 return -ENODEV; 293 } 294 static inline unsigned long ftrace_find_rec_direct(unsigned long ip) 295 { 296 return 0; 297 } 298 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 299 300 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 301 /* 302 * This must be implemented by the architecture. 303 * It is the way the ftrace direct_ops helper, when called 304 * via ftrace (because there's other callbacks besides the 305 * direct call), can inform the architecture's trampoline that this 306 * routine has a direct caller, and what the caller is. 307 * 308 * For example, in x86, it returns the direct caller 309 * callback function via the regs->orig_ax parameter. 310 * Then in the ftrace trampoline, if this is set, it makes 311 * the return from the trampoline jump to the direct caller 312 * instead of going back to the function it just traced. 313 */ 314 static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, 315 unsigned long addr) { } 316 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 317 318 #ifdef CONFIG_STACK_TRACER 319 320 extern int stack_tracer_enabled; 321 322 int stack_trace_sysctl(struct ctl_table *table, int write, 323 void __user *buffer, size_t *lenp, 324 loff_t *ppos); 325 326 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 327 DECLARE_PER_CPU(int, disable_stack_tracer); 328 329 /** 330 * stack_tracer_disable - temporarily disable the stack tracer 331 * 332 * There's a few locations (namely in RCU) where stack tracing 333 * cannot be executed. This function is used to disable stack 334 * tracing during those critical sections. 335 * 336 * This function must be called with preemption or interrupts 337 * disabled and stack_tracer_enable() must be called shortly after 338 * while preemption or interrupts are still disabled. 339 */ 340 static inline void stack_tracer_disable(void) 341 { 342 /* Preemption or interupts must be disabled */ 343 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 344 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 345 this_cpu_inc(disable_stack_tracer); 346 } 347 348 /** 349 * stack_tracer_enable - re-enable the stack tracer 350 * 351 * After stack_tracer_disable() is called, stack_tracer_enable() 352 * must be called shortly afterward. 353 */ 354 static inline void stack_tracer_enable(void) 355 { 356 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 357 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 358 this_cpu_dec(disable_stack_tracer); 359 } 360 #else 361 static inline void stack_tracer_disable(void) { } 362 static inline void stack_tracer_enable(void) { } 363 #endif 364 365 #ifdef CONFIG_DYNAMIC_FTRACE 366 367 int ftrace_arch_code_modify_prepare(void); 368 int ftrace_arch_code_modify_post_process(void); 369 370 enum ftrace_bug_type { 371 FTRACE_BUG_UNKNOWN, 372 FTRACE_BUG_INIT, 373 FTRACE_BUG_NOP, 374 FTRACE_BUG_CALL, 375 FTRACE_BUG_UPDATE, 376 }; 377 extern enum ftrace_bug_type ftrace_bug_type; 378 379 /* 380 * Archs can set this to point to a variable that holds the value that was 381 * expected at the call site before calling ftrace_bug(). 382 */ 383 extern const void *ftrace_expected; 384 385 void ftrace_bug(int err, struct dyn_ftrace *rec); 386 387 struct seq_file; 388 389 extern int ftrace_text_reserved(const void *start, const void *end); 390 391 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); 392 393 bool is_ftrace_trampoline(unsigned long addr); 394 395 /* 396 * The dyn_ftrace record's flags field is split into two parts. 397 * the first part which is '0-FTRACE_REF_MAX' is a counter of 398 * the number of callbacks that have registered the function that 399 * the dyn_ftrace descriptor represents. 400 * 401 * The second part is a mask: 402 * ENABLED - the function is being traced 403 * REGS - the record wants the function to save regs 404 * REGS_EN - the function is set up to save regs. 405 * IPMODIFY - the record allows for the IP address to be changed. 406 * DISABLED - the record is not ready to be touched yet 407 * DIRECT - there is a direct function to call 408 * 409 * When a new ftrace_ops is registered and wants a function to save 410 * pt_regs, the rec->flag REGS is set. When the function has been 411 * set up to save regs, the REG_EN flag is set. Once a function 412 * starts saving regs it will do so until all ftrace_ops are removed 413 * from tracing that function. 414 */ 415 enum { 416 FTRACE_FL_ENABLED = (1UL << 31), 417 FTRACE_FL_REGS = (1UL << 30), 418 FTRACE_FL_REGS_EN = (1UL << 29), 419 FTRACE_FL_TRAMP = (1UL << 28), 420 FTRACE_FL_TRAMP_EN = (1UL << 27), 421 FTRACE_FL_IPMODIFY = (1UL << 26), 422 FTRACE_FL_DISABLED = (1UL << 25), 423 FTRACE_FL_DIRECT = (1UL << 24), 424 FTRACE_FL_DIRECT_EN = (1UL << 23), 425 }; 426 427 #define FTRACE_REF_MAX_SHIFT 23 428 #define FTRACE_FL_BITS 9 429 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 430 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 431 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 432 433 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 434 435 struct dyn_ftrace { 436 unsigned long ip; /* address of mcount call-site */ 437 unsigned long flags; 438 struct dyn_arch_ftrace arch; 439 }; 440 441 int ftrace_force_update(void); 442 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 443 int remove, int reset); 444 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 445 int len, int reset); 446 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 447 int len, int reset); 448 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 449 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 450 void ftrace_free_filter(struct ftrace_ops *ops); 451 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 452 453 enum { 454 FTRACE_UPDATE_CALLS = (1 << 0), 455 FTRACE_DISABLE_CALLS = (1 << 1), 456 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 457 FTRACE_START_FUNC_RET = (1 << 3), 458 FTRACE_STOP_FUNC_RET = (1 << 4), 459 FTRACE_MAY_SLEEP = (1 << 5), 460 }; 461 462 /* 463 * The FTRACE_UPDATE_* enum is used to pass information back 464 * from the ftrace_update_record() and ftrace_test_record() 465 * functions. These are called by the code update routines 466 * to find out what is to be done for a given function. 467 * 468 * IGNORE - The function is already what we want it to be 469 * MAKE_CALL - Start tracing the function 470 * MODIFY_CALL - Stop saving regs for the function 471 * MAKE_NOP - Stop tracing the function 472 */ 473 enum { 474 FTRACE_UPDATE_IGNORE, 475 FTRACE_UPDATE_MAKE_CALL, 476 FTRACE_UPDATE_MODIFY_CALL, 477 FTRACE_UPDATE_MAKE_NOP, 478 }; 479 480 enum { 481 FTRACE_ITER_FILTER = (1 << 0), 482 FTRACE_ITER_NOTRACE = (1 << 1), 483 FTRACE_ITER_PRINTALL = (1 << 2), 484 FTRACE_ITER_DO_PROBES = (1 << 3), 485 FTRACE_ITER_PROBE = (1 << 4), 486 FTRACE_ITER_MOD = (1 << 5), 487 FTRACE_ITER_ENABLED = (1 << 6), 488 }; 489 490 void arch_ftrace_update_code(int command); 491 void arch_ftrace_update_trampoline(struct ftrace_ops *ops); 492 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec); 493 void arch_ftrace_trampoline_free(struct ftrace_ops *ops); 494 495 struct ftrace_rec_iter; 496 497 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 498 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 499 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 500 501 #define for_ftrace_rec_iter(iter) \ 502 for (iter = ftrace_rec_iter_start(); \ 503 iter; \ 504 iter = ftrace_rec_iter_next(iter)) 505 506 507 int ftrace_update_record(struct dyn_ftrace *rec, bool enable); 508 int ftrace_test_record(struct dyn_ftrace *rec, bool enable); 509 void ftrace_run_stop_machine(int command); 510 unsigned long ftrace_location(unsigned long ip); 511 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 512 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 513 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 514 515 extern ftrace_func_t ftrace_trace_function; 516 517 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 518 struct inode *inode, struct file *file); 519 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 520 size_t cnt, loff_t *ppos); 521 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 522 size_t cnt, loff_t *ppos); 523 int ftrace_regex_release(struct inode *inode, struct file *file); 524 525 void __init 526 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 527 528 /* defined in arch */ 529 extern int ftrace_ip_converted(unsigned long ip); 530 extern int ftrace_dyn_arch_init(void); 531 extern void ftrace_replace_code(int enable); 532 extern int ftrace_update_ftrace_func(ftrace_func_t func); 533 extern void ftrace_caller(void); 534 extern void ftrace_regs_caller(void); 535 extern void ftrace_call(void); 536 extern void ftrace_regs_call(void); 537 extern void mcount_call(void); 538 539 void ftrace_modify_all_code(int command); 540 541 #ifndef FTRACE_ADDR 542 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 543 #endif 544 545 #ifndef FTRACE_GRAPH_ADDR 546 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 547 #endif 548 549 #ifndef FTRACE_REGS_ADDR 550 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 551 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 552 #else 553 # define FTRACE_REGS_ADDR FTRACE_ADDR 554 #endif 555 #endif 556 557 /* 558 * If an arch would like functions that are only traced 559 * by the function graph tracer to jump directly to its own 560 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 561 * to be that address to jump to. 562 */ 563 #ifndef FTRACE_GRAPH_TRAMP_ADDR 564 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 565 #endif 566 567 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 568 extern void ftrace_graph_caller(void); 569 extern int ftrace_enable_ftrace_graph_caller(void); 570 extern int ftrace_disable_ftrace_graph_caller(void); 571 #else 572 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 573 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 574 #endif 575 576 /** 577 * ftrace_make_nop - convert code into nop 578 * @mod: module structure if called by module load initialization 579 * @rec: the call site record (e.g. mcount/fentry) 580 * @addr: the address that the call site should be calling 581 * 582 * This is a very sensitive operation and great care needs 583 * to be taken by the arch. The operation should carefully 584 * read the location, check to see if what is read is indeed 585 * what we expect it to be, and then on success of the compare, 586 * it should write to the location. 587 * 588 * The code segment at @rec->ip should be a caller to @addr 589 * 590 * Return must be: 591 * 0 on success 592 * -EFAULT on error reading the location 593 * -EINVAL on a failed compare of the contents 594 * -EPERM on error writing to the location 595 * Any other value will be considered a failure. 596 */ 597 extern int ftrace_make_nop(struct module *mod, 598 struct dyn_ftrace *rec, unsigned long addr); 599 600 601 /** 602 * ftrace_init_nop - initialize a nop call site 603 * @mod: module structure if called by module load initialization 604 * @rec: the call site record (e.g. mcount/fentry) 605 * 606 * This is a very sensitive operation and great care needs 607 * to be taken by the arch. The operation should carefully 608 * read the location, check to see if what is read is indeed 609 * what we expect it to be, and then on success of the compare, 610 * it should write to the location. 611 * 612 * The code segment at @rec->ip should contain the contents created by 613 * the compiler 614 * 615 * Return must be: 616 * 0 on success 617 * -EFAULT on error reading the location 618 * -EINVAL on a failed compare of the contents 619 * -EPERM on error writing to the location 620 * Any other value will be considered a failure. 621 */ 622 #ifndef ftrace_init_nop 623 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) 624 { 625 return ftrace_make_nop(mod, rec, MCOUNT_ADDR); 626 } 627 #endif 628 629 /** 630 * ftrace_make_call - convert a nop call site into a call to addr 631 * @rec: the call site record (e.g. mcount/fentry) 632 * @addr: the address that the call site should call 633 * 634 * This is a very sensitive operation and great care needs 635 * to be taken by the arch. The operation should carefully 636 * read the location, check to see if what is read is indeed 637 * what we expect it to be, and then on success of the compare, 638 * it should write to the location. 639 * 640 * The code segment at @rec->ip should be a nop 641 * 642 * Return must be: 643 * 0 on success 644 * -EFAULT on error reading the location 645 * -EINVAL on a failed compare of the contents 646 * -EPERM on error writing to the location 647 * Any other value will be considered a failure. 648 */ 649 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 650 651 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 652 /** 653 * ftrace_modify_call - convert from one addr to another (no nop) 654 * @rec: the call site record (e.g. mcount/fentry) 655 * @old_addr: the address expected to be currently called to 656 * @addr: the address to change to 657 * 658 * This is a very sensitive operation and great care needs 659 * to be taken by the arch. The operation should carefully 660 * read the location, check to see if what is read is indeed 661 * what we expect it to be, and then on success of the compare, 662 * it should write to the location. 663 * 664 * The code segment at @rec->ip should be a caller to @old_addr 665 * 666 * Return must be: 667 * 0 on success 668 * -EFAULT on error reading the location 669 * -EINVAL on a failed compare of the contents 670 * -EPERM on error writing to the location 671 * Any other value will be considered a failure. 672 */ 673 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 674 unsigned long addr); 675 #else 676 /* Should never be called */ 677 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 678 unsigned long addr) 679 { 680 return -EINVAL; 681 } 682 #endif 683 684 /* May be defined in arch */ 685 extern int ftrace_arch_read_dyn_info(char *buf, int size); 686 687 extern int skip_trace(unsigned long ip); 688 extern void ftrace_module_init(struct module *mod); 689 extern void ftrace_module_enable(struct module *mod); 690 extern void ftrace_release_mod(struct module *mod); 691 692 extern void ftrace_disable_daemon(void); 693 extern void ftrace_enable_daemon(void); 694 #else /* CONFIG_DYNAMIC_FTRACE */ 695 static inline int skip_trace(unsigned long ip) { return 0; } 696 static inline int ftrace_force_update(void) { return 0; } 697 static inline void ftrace_disable_daemon(void) { } 698 static inline void ftrace_enable_daemon(void) { } 699 static inline void ftrace_module_init(struct module *mod) { } 700 static inline void ftrace_module_enable(struct module *mod) { } 701 static inline void ftrace_release_mod(struct module *mod) { } 702 static inline int ftrace_text_reserved(const void *start, const void *end) 703 { 704 return 0; 705 } 706 static inline unsigned long ftrace_location(unsigned long ip) 707 { 708 return 0; 709 } 710 711 /* 712 * Again users of functions that have ftrace_ops may not 713 * have them defined when ftrace is not enabled, but these 714 * functions may still be called. Use a macro instead of inline. 715 */ 716 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 717 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 718 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 719 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 720 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 721 #define ftrace_free_filter(ops) do { } while (0) 722 #define ftrace_ops_set_global_filter(ops) do { } while (0) 723 724 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 725 size_t cnt, loff_t *ppos) { return -ENODEV; } 726 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 727 size_t cnt, loff_t *ppos) { return -ENODEV; } 728 static inline int 729 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 730 731 static inline bool is_ftrace_trampoline(unsigned long addr) 732 { 733 return false; 734 } 735 #endif /* CONFIG_DYNAMIC_FTRACE */ 736 737 /* totally disable ftrace - can not re-enable after this */ 738 void ftrace_kill(void); 739 740 static inline void tracer_disable(void) 741 { 742 #ifdef CONFIG_FUNCTION_TRACER 743 ftrace_enabled = 0; 744 #endif 745 } 746 747 /* 748 * Ftrace disable/restore without lock. Some synchronization mechanism 749 * must be used to prevent ftrace_enabled to be changed between 750 * disable/restore. 751 */ 752 static inline int __ftrace_enabled_save(void) 753 { 754 #ifdef CONFIG_FUNCTION_TRACER 755 int saved_ftrace_enabled = ftrace_enabled; 756 ftrace_enabled = 0; 757 return saved_ftrace_enabled; 758 #else 759 return 0; 760 #endif 761 } 762 763 static inline void __ftrace_enabled_restore(int enabled) 764 { 765 #ifdef CONFIG_FUNCTION_TRACER 766 ftrace_enabled = enabled; 767 #endif 768 } 769 770 /* All archs should have this, but we define it for consistency */ 771 #ifndef ftrace_return_address0 772 # define ftrace_return_address0 __builtin_return_address(0) 773 #endif 774 775 /* Archs may use other ways for ADDR1 and beyond */ 776 #ifndef ftrace_return_address 777 # ifdef CONFIG_FRAME_POINTER 778 # define ftrace_return_address(n) __builtin_return_address(n) 779 # else 780 # define ftrace_return_address(n) 0UL 781 # endif 782 #endif 783 784 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 785 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 786 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 787 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 788 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 789 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 790 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 791 792 static inline unsigned long get_lock_parent_ip(void) 793 { 794 unsigned long addr = CALLER_ADDR0; 795 796 if (!in_lock_functions(addr)) 797 return addr; 798 addr = CALLER_ADDR1; 799 if (!in_lock_functions(addr)) 800 return addr; 801 return CALLER_ADDR2; 802 } 803 804 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE 805 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 806 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 807 #else 808 /* 809 * Use defines instead of static inlines because some arches will make code out 810 * of the CALLER_ADDR, when we really want these to be a real nop. 811 */ 812 # define trace_preempt_on(a0, a1) do { } while (0) 813 # define trace_preempt_off(a0, a1) do { } while (0) 814 #endif 815 816 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 817 extern void ftrace_init(void); 818 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY 819 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries" 820 #else 821 #define FTRACE_CALLSITE_SECTION "__mcount_loc" 822 #endif 823 #else 824 static inline void ftrace_init(void) { } 825 #endif 826 827 /* 828 * Structure that defines an entry function trace. 829 * It's already packed but the attribute "packed" is needed 830 * to remove extra padding at the end. 831 */ 832 struct ftrace_graph_ent { 833 unsigned long func; /* Current function */ 834 int depth; 835 } __packed; 836 837 /* 838 * Structure that defines a return function trace. 839 * It's already packed but the attribute "packed" is needed 840 * to remove extra padding at the end. 841 */ 842 struct ftrace_graph_ret { 843 unsigned long func; /* Current function */ 844 /* Number of functions that overran the depth limit for current task */ 845 unsigned long overrun; 846 unsigned long long calltime; 847 unsigned long long rettime; 848 int depth; 849 } __packed; 850 851 /* Type of the callback handlers for tracing function graph*/ 852 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 853 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 854 855 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); 856 857 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 858 859 struct fgraph_ops { 860 trace_func_graph_ent_t entryfunc; 861 trace_func_graph_ret_t retfunc; 862 }; 863 864 /* 865 * Stack of return addresses for functions 866 * of a thread. 867 * Used in struct thread_info 868 */ 869 struct ftrace_ret_stack { 870 unsigned long ret; 871 unsigned long func; 872 unsigned long long calltime; 873 #ifdef CONFIG_FUNCTION_PROFILER 874 unsigned long long subtime; 875 #endif 876 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 877 unsigned long fp; 878 #endif 879 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 880 unsigned long *retp; 881 #endif 882 }; 883 884 /* 885 * Primary handler of a function return. 886 * It relays on ftrace_return_to_handler. 887 * Defined in entry_32/64.S 888 */ 889 extern void return_to_handler(void); 890 891 extern int 892 function_graph_enter(unsigned long ret, unsigned long func, 893 unsigned long frame_pointer, unsigned long *retp); 894 895 struct ftrace_ret_stack * 896 ftrace_graph_get_ret_stack(struct task_struct *task, int idx); 897 898 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 899 unsigned long ret, unsigned long *retp); 900 901 /* 902 * Sometimes we don't want to trace a function with the function 903 * graph tracer but we want them to keep traced by the usual function 904 * tracer if the function graph tracer is not configured. 905 */ 906 #define __notrace_funcgraph notrace 907 908 #define FTRACE_RETFUNC_DEPTH 50 909 #define FTRACE_RETSTACK_ALLOC_SIZE 32 910 911 extern int register_ftrace_graph(struct fgraph_ops *ops); 912 extern void unregister_ftrace_graph(struct fgraph_ops *ops); 913 914 extern bool ftrace_graph_is_dead(void); 915 extern void ftrace_graph_stop(void); 916 917 /* The current handlers in use */ 918 extern trace_func_graph_ret_t ftrace_graph_return; 919 extern trace_func_graph_ent_t ftrace_graph_entry; 920 921 extern void ftrace_graph_init_task(struct task_struct *t); 922 extern void ftrace_graph_exit_task(struct task_struct *t); 923 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 924 925 static inline void pause_graph_tracing(void) 926 { 927 atomic_inc(¤t->tracing_graph_pause); 928 } 929 930 static inline void unpause_graph_tracing(void) 931 { 932 atomic_dec(¤t->tracing_graph_pause); 933 } 934 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 935 936 #define __notrace_funcgraph 937 938 static inline void ftrace_graph_init_task(struct task_struct *t) { } 939 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 940 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 941 942 /* Define as macros as fgraph_ops may not be defined */ 943 #define register_ftrace_graph(ops) ({ -1; }) 944 #define unregister_ftrace_graph(ops) do { } while (0) 945 946 static inline unsigned long 947 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 948 unsigned long *retp) 949 { 950 return ret; 951 } 952 953 static inline void pause_graph_tracing(void) { } 954 static inline void unpause_graph_tracing(void) { } 955 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 956 957 #ifdef CONFIG_TRACING 958 959 /* flags for current->trace */ 960 enum { 961 TSK_TRACE_FL_TRACE_BIT = 0, 962 TSK_TRACE_FL_GRAPH_BIT = 1, 963 }; 964 enum { 965 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 966 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 967 }; 968 969 static inline void set_tsk_trace_trace(struct task_struct *tsk) 970 { 971 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 972 } 973 974 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 975 { 976 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 977 } 978 979 static inline int test_tsk_trace_trace(struct task_struct *tsk) 980 { 981 return tsk->trace & TSK_TRACE_FL_TRACE; 982 } 983 984 static inline void set_tsk_trace_graph(struct task_struct *tsk) 985 { 986 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 987 } 988 989 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 990 { 991 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 992 } 993 994 static inline int test_tsk_trace_graph(struct task_struct *tsk) 995 { 996 return tsk->trace & TSK_TRACE_FL_GRAPH; 997 } 998 999 enum ftrace_dump_mode; 1000 1001 extern enum ftrace_dump_mode ftrace_dump_on_oops; 1002 extern int tracepoint_printk; 1003 1004 extern void disable_trace_on_warning(void); 1005 extern int __disable_trace_on_warning; 1006 1007 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 1008 void __user *buffer, size_t *lenp, 1009 loff_t *ppos); 1010 1011 #else /* CONFIG_TRACING */ 1012 static inline void disable_trace_on_warning(void) { } 1013 #endif /* CONFIG_TRACING */ 1014 1015 #ifdef CONFIG_FTRACE_SYSCALLS 1016 1017 unsigned long arch_syscall_addr(int nr); 1018 1019 #endif /* CONFIG_FTRACE_SYSCALLS */ 1020 1021 #endif /* _LINUX_FTRACE_H */ 1022