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_recursion.h> 11 #include <linux/trace_clock.h> 12 #include <linux/kallsyms.h> 13 #include <linux/linkage.h> 14 #include <linux/bitops.h> 15 #include <linux/ptrace.h> 16 #include <linux/ktime.h> 17 #include <linux/sched.h> 18 #include <linux/types.h> 19 #include <linux/init.h> 20 #include <linux/fs.h> 21 22 #include <asm/ftrace.h> 23 24 /* 25 * If the arch supports passing the variable contents of 26 * function_trace_op as the third parameter back from the 27 * mcount call, then the arch should define this as 1. 28 */ 29 #ifndef ARCH_SUPPORTS_FTRACE_OPS 30 #define ARCH_SUPPORTS_FTRACE_OPS 0 31 #endif 32 33 #ifdef CONFIG_FUNCTION_TRACER 34 struct ftrace_ops; 35 struct ftrace_regs; 36 /* 37 * If the arch's mcount caller does not support all of ftrace's 38 * features, then it must call an indirect function that 39 * does. Or at least does enough to prevent any unwelcome side effects. 40 * 41 * Also define the function prototype that these architectures use 42 * to call the ftrace_ops_list_func(). 43 */ 44 #if !ARCH_SUPPORTS_FTRACE_OPS 45 # define FTRACE_FORCE_LIST_FUNC 1 46 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); 47 #else 48 # define FTRACE_FORCE_LIST_FUNC 0 49 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, 50 struct ftrace_ops *op, struct ftrace_regs *fregs); 51 #endif 52 #endif /* CONFIG_FUNCTION_TRACER */ 53 54 /* Main tracing buffer and events set up */ 55 #ifdef CONFIG_TRACING 56 void trace_init(void); 57 void early_trace_init(void); 58 #else 59 static inline void trace_init(void) { } 60 static inline void early_trace_init(void) { } 61 #endif 62 63 struct module; 64 struct ftrace_hash; 65 struct ftrace_direct_func; 66 67 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \ 68 defined(CONFIG_DYNAMIC_FTRACE) 69 const char * 70 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 71 unsigned long *off, char **modname, char *sym); 72 #else 73 static inline const char * 74 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 75 unsigned long *off, char **modname, char *sym) 76 { 77 return NULL; 78 } 79 #endif 80 81 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE) 82 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 83 char *type, char *name, 84 char *module_name, int *exported); 85 #else 86 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 87 char *type, char *name, 88 char *module_name, int *exported) 89 { 90 return -1; 91 } 92 #endif 93 94 #ifdef CONFIG_FUNCTION_TRACER 95 96 extern int ftrace_enabled; 97 extern int 98 ftrace_enable_sysctl(struct ctl_table *table, int write, 99 void *buffer, size_t *lenp, loff_t *ppos); 100 101 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS 102 103 struct ftrace_regs { 104 struct pt_regs regs; 105 }; 106 #define arch_ftrace_get_regs(fregs) (&(fregs)->regs) 107 108 /* 109 * ftrace_instruction_pointer_set() is to be defined by the architecture 110 * if to allow setting of the instruction pointer from the ftrace_regs 111 * when HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports 112 * live kernel patching. 113 */ 114 #define ftrace_instruction_pointer_set(fregs, ip) do { } while (0) 115 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */ 116 117 static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs) 118 { 119 if (!fregs) 120 return NULL; 121 122 return arch_ftrace_get_regs(fregs); 123 } 124 125 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 126 struct ftrace_ops *op, struct ftrace_regs *fregs); 127 128 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 129 130 /* 131 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 132 * set in the flags member. 133 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and 134 * IPMODIFY are a kind of attribute flags which can be set only before 135 * registering the ftrace_ops, and can not be modified while registered. 136 * Changing those attribute flags after registering ftrace_ops will 137 * cause unexpected results. 138 * 139 * ENABLED - set/unset when ftrace_ops is registered/unregistered 140 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 141 * allocated ftrace_ops which need special care 142 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 143 * and passed to the callback. If this flag is set, but the 144 * architecture does not support passing regs 145 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 146 * ftrace_ops will fail to register, unless the next flag 147 * is set. 148 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 149 * handler can handle an arch that does not save regs 150 * (the handler tests if regs == NULL), then it can set 151 * this flag instead. It will not fail registering the ftrace_ops 152 * but, the regs field will be NULL if the arch does not support 153 * passing regs to the handler. 154 * Note, if this flag is set, the SAVE_REGS flag will automatically 155 * get set upon registering the ftrace_ops, if the arch supports it. 156 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure 157 * that the call back needs recursion protection. If it does 158 * not set this, then the ftrace infrastructure will assume 159 * that the callback can handle recursion on its own. 160 * STUB - The ftrace_ops is just a place holder. 161 * INITIALIZED - The ftrace_ops has already been initialized (first use time 162 * register_ftrace_function() is called, it will initialized the ops) 163 * DELETED - The ops are being deleted, do not let them be registered again. 164 * ADDING - The ops is in the process of being added. 165 * REMOVING - The ops is in the process of being removed. 166 * MODIFYING - The ops is in the process of changing its filter functions. 167 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 168 * The arch specific code sets this flag when it allocated a 169 * trampoline. This lets the arch know that it can update the 170 * trampoline in case the callback function changes. 171 * The ftrace_ops trampoline can be set by the ftrace users, and 172 * in such cases the arch must not modify it. Only the arch ftrace 173 * core code should set this flag. 174 * IPMODIFY - The ops can modify the IP register. This can only be set with 175 * SAVE_REGS. If another ops with this flag set is already registered 176 * for any of the functions that this ops will be registered for, then 177 * this ops will fail to register or set_filter_ip. 178 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 179 * RCU - Set when the ops can only be called when RCU is watching. 180 * TRACE_ARRAY - The ops->private points to a trace_array descriptor. 181 * PERMANENT - Set when the ops is permanent and should not be affected by 182 * ftrace_enabled. 183 * DIRECT - Used by the direct ftrace_ops helper for direct functions 184 * (internal ftrace only, should not be used by others) 185 */ 186 enum { 187 FTRACE_OPS_FL_ENABLED = BIT(0), 188 FTRACE_OPS_FL_DYNAMIC = BIT(1), 189 FTRACE_OPS_FL_SAVE_REGS = BIT(2), 190 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3), 191 FTRACE_OPS_FL_RECURSION = BIT(4), 192 FTRACE_OPS_FL_STUB = BIT(5), 193 FTRACE_OPS_FL_INITIALIZED = BIT(6), 194 FTRACE_OPS_FL_DELETED = BIT(7), 195 FTRACE_OPS_FL_ADDING = BIT(8), 196 FTRACE_OPS_FL_REMOVING = BIT(9), 197 FTRACE_OPS_FL_MODIFYING = BIT(10), 198 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11), 199 FTRACE_OPS_FL_IPMODIFY = BIT(12), 200 FTRACE_OPS_FL_PID = BIT(13), 201 FTRACE_OPS_FL_RCU = BIT(14), 202 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15), 203 FTRACE_OPS_FL_PERMANENT = BIT(16), 204 FTRACE_OPS_FL_DIRECT = BIT(17), 205 }; 206 207 #ifdef CONFIG_DYNAMIC_FTRACE 208 /* The hash used to know what functions callbacks trace */ 209 struct ftrace_ops_hash { 210 struct ftrace_hash __rcu *notrace_hash; 211 struct ftrace_hash __rcu *filter_hash; 212 struct mutex regex_lock; 213 }; 214 215 void ftrace_free_init_mem(void); 216 void ftrace_free_mem(struct module *mod, void *start, void *end); 217 #else 218 static inline void ftrace_free_init_mem(void) { } 219 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 220 #endif 221 222 /* 223 * Note, ftrace_ops can be referenced outside of RCU protection, unless 224 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel 225 * core data, the unregistering of it will perform a scheduling on all CPUs 226 * to make sure that there are no more users. Depending on the load of the 227 * system that may take a bit of time. 228 * 229 * Any private data added must also take care not to be freed and if private 230 * data is added to a ftrace_ops that is in core code, the user of the 231 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 232 */ 233 struct ftrace_ops { 234 ftrace_func_t func; 235 struct ftrace_ops __rcu *next; 236 unsigned long flags; 237 void *private; 238 ftrace_func_t saved_func; 239 #ifdef CONFIG_DYNAMIC_FTRACE 240 struct ftrace_ops_hash local_hash; 241 struct ftrace_ops_hash *func_hash; 242 struct ftrace_ops_hash old_hash; 243 unsigned long trampoline; 244 unsigned long trampoline_size; 245 struct list_head list; 246 #endif 247 }; 248 249 extern struct ftrace_ops __rcu *ftrace_ops_list; 250 extern struct ftrace_ops ftrace_list_end; 251 252 /* 253 * Traverse the ftrace_ops_list, invoking all entries. The reason that we 254 * can use rcu_dereference_raw_check() is that elements removed from this list 255 * are simply leaked, so there is no need to interact with a grace-period 256 * mechanism. The rcu_dereference_raw_check() calls are needed to handle 257 * concurrent insertions into the ftrace_ops_list. 258 * 259 * Silly Alpha and silly pointer-speculation compiler optimizations! 260 */ 261 #define do_for_each_ftrace_op(op, list) \ 262 op = rcu_dereference_raw_check(list); \ 263 do 264 265 /* 266 * Optimized for just a single item in the list (as that is the normal case). 267 */ 268 #define while_for_each_ftrace_op(op) \ 269 while (likely(op = rcu_dereference_raw_check((op)->next)) && \ 270 unlikely((op) != &ftrace_list_end)) 271 272 /* 273 * Type of the current tracing. 274 */ 275 enum ftrace_tracing_type_t { 276 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 277 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 278 }; 279 280 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 281 extern enum ftrace_tracing_type_t ftrace_tracing_type; 282 283 /* 284 * The ftrace_ops must be a static and should also 285 * be read_mostly. These functions do modify read_mostly variables 286 * so use them sparely. Never free an ftrace_op or modify the 287 * next pointer after it has been registered. Even after unregistering 288 * it, the next pointer may still be used internally. 289 */ 290 int register_ftrace_function(struct ftrace_ops *ops); 291 int unregister_ftrace_function(struct ftrace_ops *ops); 292 293 extern void ftrace_stub(unsigned long a0, unsigned long a1, 294 struct ftrace_ops *op, struct ftrace_regs *fregs); 295 296 #else /* !CONFIG_FUNCTION_TRACER */ 297 /* 298 * (un)register_ftrace_function must be a macro since the ops parameter 299 * must not be evaluated. 300 */ 301 #define register_ftrace_function(ops) ({ 0; }) 302 #define unregister_ftrace_function(ops) ({ 0; }) 303 static inline void ftrace_kill(void) { } 304 static inline void ftrace_free_init_mem(void) { } 305 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 306 #endif /* CONFIG_FUNCTION_TRACER */ 307 308 struct ftrace_func_entry { 309 struct hlist_node hlist; 310 unsigned long ip; 311 unsigned long direct; /* for direct lookup only */ 312 }; 313 314 struct dyn_ftrace; 315 316 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 317 extern int ftrace_direct_func_count; 318 int register_ftrace_direct(unsigned long ip, unsigned long addr); 319 int unregister_ftrace_direct(unsigned long ip, unsigned long addr); 320 int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr); 321 struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr); 322 int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 323 struct dyn_ftrace *rec, 324 unsigned long old_addr, 325 unsigned long new_addr); 326 unsigned long ftrace_find_rec_direct(unsigned long ip); 327 int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); 328 int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); 329 int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); 330 331 #else 332 struct ftrace_ops; 333 # define ftrace_direct_func_count 0 334 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr) 335 { 336 return -ENOTSUPP; 337 } 338 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr) 339 { 340 return -ENOTSUPP; 341 } 342 static inline int modify_ftrace_direct(unsigned long ip, 343 unsigned long old_addr, unsigned long new_addr) 344 { 345 return -ENOTSUPP; 346 } 347 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) 348 { 349 return NULL; 350 } 351 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 352 struct dyn_ftrace *rec, 353 unsigned long old_addr, 354 unsigned long new_addr) 355 { 356 return -ENODEV; 357 } 358 static inline unsigned long ftrace_find_rec_direct(unsigned long ip) 359 { 360 return 0; 361 } 362 static inline int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 363 { 364 return -ENODEV; 365 } 366 static inline int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 367 { 368 return -ENODEV; 369 } 370 static inline int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 371 { 372 return -ENODEV; 373 } 374 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 375 376 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 377 /* 378 * This must be implemented by the architecture. 379 * It is the way the ftrace direct_ops helper, when called 380 * via ftrace (because there's other callbacks besides the 381 * direct call), can inform the architecture's trampoline that this 382 * routine has a direct caller, and what the caller is. 383 * 384 * For example, in x86, it returns the direct caller 385 * callback function via the regs->orig_ax parameter. 386 * Then in the ftrace trampoline, if this is set, it makes 387 * the return from the trampoline jump to the direct caller 388 * instead of going back to the function it just traced. 389 */ 390 static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, 391 unsigned long addr) { } 392 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 393 394 #ifdef CONFIG_STACK_TRACER 395 396 extern int stack_tracer_enabled; 397 398 int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer, 399 size_t *lenp, loff_t *ppos); 400 401 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 402 DECLARE_PER_CPU(int, disable_stack_tracer); 403 404 /** 405 * stack_tracer_disable - temporarily disable the stack tracer 406 * 407 * There's a few locations (namely in RCU) where stack tracing 408 * cannot be executed. This function is used to disable stack 409 * tracing during those critical sections. 410 * 411 * This function must be called with preemption or interrupts 412 * disabled and stack_tracer_enable() must be called shortly after 413 * while preemption or interrupts are still disabled. 414 */ 415 static inline void stack_tracer_disable(void) 416 { 417 /* Preemption or interrupts must be disabled */ 418 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 419 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 420 this_cpu_inc(disable_stack_tracer); 421 } 422 423 /** 424 * stack_tracer_enable - re-enable the stack tracer 425 * 426 * After stack_tracer_disable() is called, stack_tracer_enable() 427 * must be called shortly afterward. 428 */ 429 static inline void stack_tracer_enable(void) 430 { 431 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 432 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 433 this_cpu_dec(disable_stack_tracer); 434 } 435 #else 436 static inline void stack_tracer_disable(void) { } 437 static inline void stack_tracer_enable(void) { } 438 #endif 439 440 #ifdef CONFIG_DYNAMIC_FTRACE 441 442 int ftrace_arch_code_modify_prepare(void); 443 int ftrace_arch_code_modify_post_process(void); 444 445 enum ftrace_bug_type { 446 FTRACE_BUG_UNKNOWN, 447 FTRACE_BUG_INIT, 448 FTRACE_BUG_NOP, 449 FTRACE_BUG_CALL, 450 FTRACE_BUG_UPDATE, 451 }; 452 extern enum ftrace_bug_type ftrace_bug_type; 453 454 /* 455 * Archs can set this to point to a variable that holds the value that was 456 * expected at the call site before calling ftrace_bug(). 457 */ 458 extern const void *ftrace_expected; 459 460 void ftrace_bug(int err, struct dyn_ftrace *rec); 461 462 struct seq_file; 463 464 extern int ftrace_text_reserved(const void *start, const void *end); 465 466 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); 467 468 bool is_ftrace_trampoline(unsigned long addr); 469 470 /* 471 * The dyn_ftrace record's flags field is split into two parts. 472 * the first part which is '0-FTRACE_REF_MAX' is a counter of 473 * the number of callbacks that have registered the function that 474 * the dyn_ftrace descriptor represents. 475 * 476 * The second part is a mask: 477 * ENABLED - the function is being traced 478 * REGS - the record wants the function to save regs 479 * REGS_EN - the function is set up to save regs. 480 * IPMODIFY - the record allows for the IP address to be changed. 481 * DISABLED - the record is not ready to be touched yet 482 * DIRECT - there is a direct function to call 483 * 484 * When a new ftrace_ops is registered and wants a function to save 485 * pt_regs, the rec->flags REGS is set. When the function has been 486 * set up to save regs, the REG_EN flag is set. Once a function 487 * starts saving regs it will do so until all ftrace_ops are removed 488 * from tracing that function. 489 */ 490 enum { 491 FTRACE_FL_ENABLED = (1UL << 31), 492 FTRACE_FL_REGS = (1UL << 30), 493 FTRACE_FL_REGS_EN = (1UL << 29), 494 FTRACE_FL_TRAMP = (1UL << 28), 495 FTRACE_FL_TRAMP_EN = (1UL << 27), 496 FTRACE_FL_IPMODIFY = (1UL << 26), 497 FTRACE_FL_DISABLED = (1UL << 25), 498 FTRACE_FL_DIRECT = (1UL << 24), 499 FTRACE_FL_DIRECT_EN = (1UL << 23), 500 }; 501 502 #define FTRACE_REF_MAX_SHIFT 23 503 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 504 505 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX) 506 507 struct dyn_ftrace { 508 unsigned long ip; /* address of mcount call-site */ 509 unsigned long flags; 510 struct dyn_arch_ftrace arch; 511 }; 512 513 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 514 int remove, int reset); 515 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, 516 unsigned int cnt, int remove, int reset); 517 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 518 int len, int reset); 519 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 520 int len, int reset); 521 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 522 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 523 void ftrace_free_filter(struct ftrace_ops *ops); 524 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 525 526 enum { 527 FTRACE_UPDATE_CALLS = (1 << 0), 528 FTRACE_DISABLE_CALLS = (1 << 1), 529 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 530 FTRACE_START_FUNC_RET = (1 << 3), 531 FTRACE_STOP_FUNC_RET = (1 << 4), 532 FTRACE_MAY_SLEEP = (1 << 5), 533 }; 534 535 /* 536 * The FTRACE_UPDATE_* enum is used to pass information back 537 * from the ftrace_update_record() and ftrace_test_record() 538 * functions. These are called by the code update routines 539 * to find out what is to be done for a given function. 540 * 541 * IGNORE - The function is already what we want it to be 542 * MAKE_CALL - Start tracing the function 543 * MODIFY_CALL - Stop saving regs for the function 544 * MAKE_NOP - Stop tracing the function 545 */ 546 enum { 547 FTRACE_UPDATE_IGNORE, 548 FTRACE_UPDATE_MAKE_CALL, 549 FTRACE_UPDATE_MODIFY_CALL, 550 FTRACE_UPDATE_MAKE_NOP, 551 }; 552 553 enum { 554 FTRACE_ITER_FILTER = (1 << 0), 555 FTRACE_ITER_NOTRACE = (1 << 1), 556 FTRACE_ITER_PRINTALL = (1 << 2), 557 FTRACE_ITER_DO_PROBES = (1 << 3), 558 FTRACE_ITER_PROBE = (1 << 4), 559 FTRACE_ITER_MOD = (1 << 5), 560 FTRACE_ITER_ENABLED = (1 << 6), 561 }; 562 563 void arch_ftrace_update_code(int command); 564 void arch_ftrace_update_trampoline(struct ftrace_ops *ops); 565 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec); 566 void arch_ftrace_trampoline_free(struct ftrace_ops *ops); 567 568 struct ftrace_rec_iter; 569 570 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 571 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 572 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 573 574 #define for_ftrace_rec_iter(iter) \ 575 for (iter = ftrace_rec_iter_start(); \ 576 iter; \ 577 iter = ftrace_rec_iter_next(iter)) 578 579 580 int ftrace_update_record(struct dyn_ftrace *rec, bool enable); 581 int ftrace_test_record(struct dyn_ftrace *rec, bool enable); 582 void ftrace_run_stop_machine(int command); 583 unsigned long ftrace_location(unsigned long ip); 584 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 585 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 586 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 587 588 extern ftrace_func_t ftrace_trace_function; 589 590 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 591 struct inode *inode, struct file *file); 592 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 593 size_t cnt, loff_t *ppos); 594 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 595 size_t cnt, loff_t *ppos); 596 int ftrace_regex_release(struct inode *inode, struct file *file); 597 598 void __init 599 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 600 601 /* defined in arch */ 602 extern int ftrace_ip_converted(unsigned long ip); 603 extern int ftrace_dyn_arch_init(void); 604 extern void ftrace_replace_code(int enable); 605 extern int ftrace_update_ftrace_func(ftrace_func_t func); 606 extern void ftrace_caller(void); 607 extern void ftrace_regs_caller(void); 608 extern void ftrace_call(void); 609 extern void ftrace_regs_call(void); 610 extern void mcount_call(void); 611 612 void ftrace_modify_all_code(int command); 613 614 #ifndef FTRACE_ADDR 615 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 616 #endif 617 618 #ifndef FTRACE_GRAPH_ADDR 619 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 620 #endif 621 622 #ifndef FTRACE_REGS_ADDR 623 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 624 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 625 #else 626 # define FTRACE_REGS_ADDR FTRACE_ADDR 627 #endif 628 #endif 629 630 /* 631 * If an arch would like functions that are only traced 632 * by the function graph tracer to jump directly to its own 633 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 634 * to be that address to jump to. 635 */ 636 #ifndef FTRACE_GRAPH_TRAMP_ADDR 637 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 638 #endif 639 640 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 641 extern void ftrace_graph_caller(void); 642 extern int ftrace_enable_ftrace_graph_caller(void); 643 extern int ftrace_disable_ftrace_graph_caller(void); 644 #else 645 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 646 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 647 #endif 648 649 /** 650 * ftrace_make_nop - convert code into nop 651 * @mod: module structure if called by module load initialization 652 * @rec: the call site record (e.g. mcount/fentry) 653 * @addr: the address that the call site should be calling 654 * 655 * This is a very sensitive operation and great care needs 656 * to be taken by the arch. The operation should carefully 657 * read the location, check to see if what is read is indeed 658 * what we expect it to be, and then on success of the compare, 659 * it should write to the location. 660 * 661 * The code segment at @rec->ip should be a caller to @addr 662 * 663 * Return must be: 664 * 0 on success 665 * -EFAULT on error reading the location 666 * -EINVAL on a failed compare of the contents 667 * -EPERM on error writing to the location 668 * Any other value will be considered a failure. 669 */ 670 extern int ftrace_make_nop(struct module *mod, 671 struct dyn_ftrace *rec, unsigned long addr); 672 673 /** 674 * ftrace_need_init_nop - return whether nop call sites should be initialized 675 * 676 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't 677 * need to call ftrace_init_nop() if the code is built with that flag. 678 * Architectures where this is not always the case may define their own 679 * condition. 680 * 681 * Return must be: 682 * 0 if ftrace_init_nop() should be called 683 * Nonzero if ftrace_init_nop() should not be called 684 */ 685 686 #ifndef ftrace_need_init_nop 687 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT)) 688 #endif 689 690 /** 691 * ftrace_init_nop - initialize a nop call site 692 * @mod: module structure if called by module load initialization 693 * @rec: the call site record (e.g. mcount/fentry) 694 * 695 * This is a very sensitive operation and great care needs 696 * to be taken by the arch. The operation should carefully 697 * read the location, check to see if what is read is indeed 698 * what we expect it to be, and then on success of the compare, 699 * it should write to the location. 700 * 701 * The code segment at @rec->ip should contain the contents created by 702 * the compiler 703 * 704 * Return must be: 705 * 0 on success 706 * -EFAULT on error reading the location 707 * -EINVAL on a failed compare of the contents 708 * -EPERM on error writing to the location 709 * Any other value will be considered a failure. 710 */ 711 #ifndef ftrace_init_nop 712 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) 713 { 714 return ftrace_make_nop(mod, rec, MCOUNT_ADDR); 715 } 716 #endif 717 718 /** 719 * ftrace_make_call - convert a nop call site into a call to addr 720 * @rec: the call site record (e.g. mcount/fentry) 721 * @addr: the address that the call site should call 722 * 723 * This is a very sensitive operation and great care needs 724 * to be taken by the arch. The operation should carefully 725 * read the location, check to see if what is read is indeed 726 * what we expect it to be, and then on success of the compare, 727 * it should write to the location. 728 * 729 * The code segment at @rec->ip should be a nop 730 * 731 * Return must be: 732 * 0 on success 733 * -EFAULT on error reading the location 734 * -EINVAL on a failed compare of the contents 735 * -EPERM on error writing to the location 736 * Any other value will be considered a failure. 737 */ 738 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 739 740 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 741 /** 742 * ftrace_modify_call - convert from one addr to another (no nop) 743 * @rec: the call site record (e.g. mcount/fentry) 744 * @old_addr: the address expected to be currently called to 745 * @addr: the address to change to 746 * 747 * This is a very sensitive operation and great care needs 748 * to be taken by the arch. The operation should carefully 749 * read the location, check to see if what is read is indeed 750 * what we expect it to be, and then on success of the compare, 751 * it should write to the location. 752 * 753 * The code segment at @rec->ip should be a caller to @old_addr 754 * 755 * Return must be: 756 * 0 on success 757 * -EFAULT on error reading the location 758 * -EINVAL on a failed compare of the contents 759 * -EPERM on error writing to the location 760 * Any other value will be considered a failure. 761 */ 762 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 763 unsigned long addr); 764 #else 765 /* Should never be called */ 766 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 767 unsigned long addr) 768 { 769 return -EINVAL; 770 } 771 #endif 772 773 /* May be defined in arch */ 774 extern int ftrace_arch_read_dyn_info(char *buf, int size); 775 776 extern int skip_trace(unsigned long ip); 777 extern void ftrace_module_init(struct module *mod); 778 extern void ftrace_module_enable(struct module *mod); 779 extern void ftrace_release_mod(struct module *mod); 780 781 extern void ftrace_disable_daemon(void); 782 extern void ftrace_enable_daemon(void); 783 #else /* CONFIG_DYNAMIC_FTRACE */ 784 static inline int skip_trace(unsigned long ip) { return 0; } 785 static inline void ftrace_disable_daemon(void) { } 786 static inline void ftrace_enable_daemon(void) { } 787 static inline void ftrace_module_init(struct module *mod) { } 788 static inline void ftrace_module_enable(struct module *mod) { } 789 static inline void ftrace_release_mod(struct module *mod) { } 790 static inline int ftrace_text_reserved(const void *start, const void *end) 791 { 792 return 0; 793 } 794 static inline unsigned long ftrace_location(unsigned long ip) 795 { 796 return 0; 797 } 798 799 /* 800 * Again users of functions that have ftrace_ops may not 801 * have them defined when ftrace is not enabled, but these 802 * functions may still be called. Use a macro instead of inline. 803 */ 804 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 805 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 806 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 807 #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; }) 808 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 809 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 810 #define ftrace_free_filter(ops) do { } while (0) 811 #define ftrace_ops_set_global_filter(ops) do { } while (0) 812 813 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 814 size_t cnt, loff_t *ppos) { return -ENODEV; } 815 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 816 size_t cnt, loff_t *ppos) { return -ENODEV; } 817 static inline int 818 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 819 820 static inline bool is_ftrace_trampoline(unsigned long addr) 821 { 822 return false; 823 } 824 #endif /* CONFIG_DYNAMIC_FTRACE */ 825 826 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 827 #ifndef ftrace_graph_func 828 #define ftrace_graph_func ftrace_stub 829 #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB 830 #else 831 #define FTRACE_OPS_GRAPH_STUB 0 832 #endif 833 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 834 835 /* totally disable ftrace - can not re-enable after this */ 836 void ftrace_kill(void); 837 838 static inline void tracer_disable(void) 839 { 840 #ifdef CONFIG_FUNCTION_TRACER 841 ftrace_enabled = 0; 842 #endif 843 } 844 845 /* 846 * Ftrace disable/restore without lock. Some synchronization mechanism 847 * must be used to prevent ftrace_enabled to be changed between 848 * disable/restore. 849 */ 850 static inline int __ftrace_enabled_save(void) 851 { 852 #ifdef CONFIG_FUNCTION_TRACER 853 int saved_ftrace_enabled = ftrace_enabled; 854 ftrace_enabled = 0; 855 return saved_ftrace_enabled; 856 #else 857 return 0; 858 #endif 859 } 860 861 static inline void __ftrace_enabled_restore(int enabled) 862 { 863 #ifdef CONFIG_FUNCTION_TRACER 864 ftrace_enabled = enabled; 865 #endif 866 } 867 868 /* All archs should have this, but we define it for consistency */ 869 #ifndef ftrace_return_address0 870 # define ftrace_return_address0 __builtin_return_address(0) 871 #endif 872 873 /* Archs may use other ways for ADDR1 and beyond */ 874 #ifndef ftrace_return_address 875 # ifdef CONFIG_FRAME_POINTER 876 # define ftrace_return_address(n) __builtin_return_address(n) 877 # else 878 # define ftrace_return_address(n) 0UL 879 # endif 880 #endif 881 882 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 883 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 884 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 885 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 886 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 887 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 888 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 889 890 static inline unsigned long get_lock_parent_ip(void) 891 { 892 unsigned long addr = CALLER_ADDR0; 893 894 if (!in_lock_functions(addr)) 895 return addr; 896 addr = CALLER_ADDR1; 897 if (!in_lock_functions(addr)) 898 return addr; 899 return CALLER_ADDR2; 900 } 901 902 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE 903 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 904 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 905 #else 906 /* 907 * Use defines instead of static inlines because some arches will make code out 908 * of the CALLER_ADDR, when we really want these to be a real nop. 909 */ 910 # define trace_preempt_on(a0, a1) do { } while (0) 911 # define trace_preempt_off(a0, a1) do { } while (0) 912 #endif 913 914 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 915 extern void ftrace_init(void); 916 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY 917 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries" 918 #else 919 #define FTRACE_CALLSITE_SECTION "__mcount_loc" 920 #endif 921 #else 922 static inline void ftrace_init(void) { } 923 #endif 924 925 /* 926 * Structure that defines an entry function trace. 927 * It's already packed but the attribute "packed" is needed 928 * to remove extra padding at the end. 929 */ 930 struct ftrace_graph_ent { 931 unsigned long func; /* Current function */ 932 int depth; 933 } __packed; 934 935 /* 936 * Structure that defines a return function trace. 937 * It's already packed but the attribute "packed" is needed 938 * to remove extra padding at the end. 939 */ 940 struct ftrace_graph_ret { 941 unsigned long func; /* Current function */ 942 int depth; 943 /* Number of functions that overran the depth limit for current task */ 944 unsigned int overrun; 945 unsigned long long calltime; 946 unsigned long long rettime; 947 } __packed; 948 949 /* Type of the callback handlers for tracing function graph*/ 950 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 951 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 952 953 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); 954 955 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 956 957 struct fgraph_ops { 958 trace_func_graph_ent_t entryfunc; 959 trace_func_graph_ret_t retfunc; 960 }; 961 962 /* 963 * Stack of return addresses for functions 964 * of a thread. 965 * Used in struct thread_info 966 */ 967 struct ftrace_ret_stack { 968 unsigned long ret; 969 unsigned long func; 970 unsigned long long calltime; 971 #ifdef CONFIG_FUNCTION_PROFILER 972 unsigned long long subtime; 973 #endif 974 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 975 unsigned long fp; 976 #endif 977 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 978 unsigned long *retp; 979 #endif 980 }; 981 982 /* 983 * Primary handler of a function return. 984 * It relays on ftrace_return_to_handler. 985 * Defined in entry_32/64.S 986 */ 987 extern void return_to_handler(void); 988 989 extern int 990 function_graph_enter(unsigned long ret, unsigned long func, 991 unsigned long frame_pointer, unsigned long *retp); 992 993 struct ftrace_ret_stack * 994 ftrace_graph_get_ret_stack(struct task_struct *task, int idx); 995 996 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 997 unsigned long ret, unsigned long *retp); 998 999 /* 1000 * Sometimes we don't want to trace a function with the function 1001 * graph tracer but we want them to keep traced by the usual function 1002 * tracer if the function graph tracer is not configured. 1003 */ 1004 #define __notrace_funcgraph notrace 1005 1006 #define FTRACE_RETFUNC_DEPTH 50 1007 #define FTRACE_RETSTACK_ALLOC_SIZE 32 1008 1009 extern int register_ftrace_graph(struct fgraph_ops *ops); 1010 extern void unregister_ftrace_graph(struct fgraph_ops *ops); 1011 1012 extern bool ftrace_graph_is_dead(void); 1013 extern void ftrace_graph_stop(void); 1014 1015 /* The current handlers in use */ 1016 extern trace_func_graph_ret_t ftrace_graph_return; 1017 extern trace_func_graph_ent_t ftrace_graph_entry; 1018 1019 extern void ftrace_graph_init_task(struct task_struct *t); 1020 extern void ftrace_graph_exit_task(struct task_struct *t); 1021 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 1022 1023 static inline void pause_graph_tracing(void) 1024 { 1025 atomic_inc(¤t->tracing_graph_pause); 1026 } 1027 1028 static inline void unpause_graph_tracing(void) 1029 { 1030 atomic_dec(¤t->tracing_graph_pause); 1031 } 1032 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 1033 1034 #define __notrace_funcgraph 1035 1036 static inline void ftrace_graph_init_task(struct task_struct *t) { } 1037 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 1038 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 1039 1040 /* Define as macros as fgraph_ops may not be defined */ 1041 #define register_ftrace_graph(ops) ({ -1; }) 1042 #define unregister_ftrace_graph(ops) do { } while (0) 1043 1044 static inline unsigned long 1045 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 1046 unsigned long *retp) 1047 { 1048 return ret; 1049 } 1050 1051 static inline void pause_graph_tracing(void) { } 1052 static inline void unpause_graph_tracing(void) { } 1053 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 1054 1055 #ifdef CONFIG_TRACING 1056 1057 /* flags for current->trace */ 1058 enum { 1059 TSK_TRACE_FL_TRACE_BIT = 0, 1060 TSK_TRACE_FL_GRAPH_BIT = 1, 1061 }; 1062 enum { 1063 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 1064 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 1065 }; 1066 1067 static inline void set_tsk_trace_trace(struct task_struct *tsk) 1068 { 1069 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 1070 } 1071 1072 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 1073 { 1074 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 1075 } 1076 1077 static inline int test_tsk_trace_trace(struct task_struct *tsk) 1078 { 1079 return tsk->trace & TSK_TRACE_FL_TRACE; 1080 } 1081 1082 static inline void set_tsk_trace_graph(struct task_struct *tsk) 1083 { 1084 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 1085 } 1086 1087 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 1088 { 1089 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 1090 } 1091 1092 static inline int test_tsk_trace_graph(struct task_struct *tsk) 1093 { 1094 return tsk->trace & TSK_TRACE_FL_GRAPH; 1095 } 1096 1097 enum ftrace_dump_mode; 1098 1099 extern enum ftrace_dump_mode ftrace_dump_on_oops; 1100 extern int tracepoint_printk; 1101 1102 extern void disable_trace_on_warning(void); 1103 extern int __disable_trace_on_warning; 1104 1105 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 1106 void *buffer, size_t *lenp, loff_t *ppos); 1107 1108 #else /* CONFIG_TRACING */ 1109 static inline void disable_trace_on_warning(void) { } 1110 #endif /* CONFIG_TRACING */ 1111 1112 #ifdef CONFIG_FTRACE_SYSCALLS 1113 1114 unsigned long arch_syscall_addr(int nr); 1115 1116 #endif /* CONFIG_FTRACE_SYSCALLS */ 1117 1118 #endif /* _LINUX_FTRACE_H */ 1119