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_TRACING 34 extern void ftrace_boot_snapshot(void); 35 #else 36 static inline void ftrace_boot_snapshot(void) { } 37 #endif 38 39 #ifdef CONFIG_FUNCTION_TRACER 40 struct ftrace_ops; 41 struct ftrace_regs; 42 /* 43 * If the arch's mcount caller does not support all of ftrace's 44 * features, then it must call an indirect function that 45 * does. Or at least does enough to prevent any unwelcome side effects. 46 * 47 * Also define the function prototype that these architectures use 48 * to call the ftrace_ops_list_func(). 49 */ 50 #if !ARCH_SUPPORTS_FTRACE_OPS 51 # define FTRACE_FORCE_LIST_FUNC 1 52 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); 53 #else 54 # define FTRACE_FORCE_LIST_FUNC 0 55 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, 56 struct ftrace_ops *op, struct ftrace_regs *fregs); 57 #endif 58 #endif /* CONFIG_FUNCTION_TRACER */ 59 60 /* Main tracing buffer and events set up */ 61 #ifdef CONFIG_TRACING 62 void trace_init(void); 63 void early_trace_init(void); 64 #else 65 static inline void trace_init(void) { } 66 static inline void early_trace_init(void) { } 67 #endif 68 69 struct module; 70 struct ftrace_hash; 71 struct ftrace_direct_func; 72 73 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \ 74 defined(CONFIG_DYNAMIC_FTRACE) 75 const char * 76 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 77 unsigned long *off, char **modname, char *sym); 78 #else 79 static inline const char * 80 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 81 unsigned long *off, char **modname, char *sym) 82 { 83 return NULL; 84 } 85 #endif 86 87 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE) 88 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 89 char *type, char *name, 90 char *module_name, int *exported); 91 #else 92 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 93 char *type, char *name, 94 char *module_name, int *exported) 95 { 96 return -1; 97 } 98 #endif 99 100 #ifdef CONFIG_FUNCTION_TRACER 101 102 extern int ftrace_enabled; 103 extern int 104 ftrace_enable_sysctl(struct ctl_table *table, int write, 105 void *buffer, size_t *lenp, loff_t *ppos); 106 107 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS 108 109 struct ftrace_regs { 110 struct pt_regs regs; 111 }; 112 #define arch_ftrace_get_regs(fregs) (&(fregs)->regs) 113 114 /* 115 * ftrace_instruction_pointer_set() is to be defined by the architecture 116 * if to allow setting of the instruction pointer from the ftrace_regs 117 * when HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports 118 * live kernel patching. 119 */ 120 #define ftrace_instruction_pointer_set(fregs, ip) do { } while (0) 121 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */ 122 123 static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs) 124 { 125 if (!fregs) 126 return NULL; 127 128 return arch_ftrace_get_regs(fregs); 129 } 130 131 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 132 struct ftrace_ops *op, struct ftrace_regs *fregs); 133 134 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 135 136 /* 137 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 138 * set in the flags member. 139 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and 140 * IPMODIFY are a kind of attribute flags which can be set only before 141 * registering the ftrace_ops, and can not be modified while registered. 142 * Changing those attribute flags after registering ftrace_ops will 143 * cause unexpected results. 144 * 145 * ENABLED - set/unset when ftrace_ops is registered/unregistered 146 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 147 * allocated ftrace_ops which need special care 148 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 149 * and passed to the callback. If this flag is set, but the 150 * architecture does not support passing regs 151 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 152 * ftrace_ops will fail to register, unless the next flag 153 * is set. 154 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 155 * handler can handle an arch that does not save regs 156 * (the handler tests if regs == NULL), then it can set 157 * this flag instead. It will not fail registering the ftrace_ops 158 * but, the regs field will be NULL if the arch does not support 159 * passing regs to the handler. 160 * Note, if this flag is set, the SAVE_REGS flag will automatically 161 * get set upon registering the ftrace_ops, if the arch supports it. 162 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure 163 * that the call back needs recursion protection. If it does 164 * not set this, then the ftrace infrastructure will assume 165 * that the callback can handle recursion on its own. 166 * STUB - The ftrace_ops is just a place holder. 167 * INITIALIZED - The ftrace_ops has already been initialized (first use time 168 * register_ftrace_function() is called, it will initialized the ops) 169 * DELETED - The ops are being deleted, do not let them be registered again. 170 * ADDING - The ops is in the process of being added. 171 * REMOVING - The ops is in the process of being removed. 172 * MODIFYING - The ops is in the process of changing its filter functions. 173 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 174 * The arch specific code sets this flag when it allocated a 175 * trampoline. This lets the arch know that it can update the 176 * trampoline in case the callback function changes. 177 * The ftrace_ops trampoline can be set by the ftrace users, and 178 * in such cases the arch must not modify it. Only the arch ftrace 179 * core code should set this flag. 180 * IPMODIFY - The ops can modify the IP register. This can only be set with 181 * SAVE_REGS. If another ops with this flag set is already registered 182 * for any of the functions that this ops will be registered for, then 183 * this ops will fail to register or set_filter_ip. 184 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 185 * RCU - Set when the ops can only be called when RCU is watching. 186 * TRACE_ARRAY - The ops->private points to a trace_array descriptor. 187 * PERMANENT - Set when the ops is permanent and should not be affected by 188 * ftrace_enabled. 189 * DIRECT - Used by the direct ftrace_ops helper for direct functions 190 * (internal ftrace only, should not be used by others) 191 */ 192 enum { 193 FTRACE_OPS_FL_ENABLED = BIT(0), 194 FTRACE_OPS_FL_DYNAMIC = BIT(1), 195 FTRACE_OPS_FL_SAVE_REGS = BIT(2), 196 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3), 197 FTRACE_OPS_FL_RECURSION = BIT(4), 198 FTRACE_OPS_FL_STUB = BIT(5), 199 FTRACE_OPS_FL_INITIALIZED = BIT(6), 200 FTRACE_OPS_FL_DELETED = BIT(7), 201 FTRACE_OPS_FL_ADDING = BIT(8), 202 FTRACE_OPS_FL_REMOVING = BIT(9), 203 FTRACE_OPS_FL_MODIFYING = BIT(10), 204 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11), 205 FTRACE_OPS_FL_IPMODIFY = BIT(12), 206 FTRACE_OPS_FL_PID = BIT(13), 207 FTRACE_OPS_FL_RCU = BIT(14), 208 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15), 209 FTRACE_OPS_FL_PERMANENT = BIT(16), 210 FTRACE_OPS_FL_DIRECT = BIT(17), 211 }; 212 213 #ifdef CONFIG_DYNAMIC_FTRACE 214 /* The hash used to know what functions callbacks trace */ 215 struct ftrace_ops_hash { 216 struct ftrace_hash __rcu *notrace_hash; 217 struct ftrace_hash __rcu *filter_hash; 218 struct mutex regex_lock; 219 }; 220 221 void ftrace_free_init_mem(void); 222 void ftrace_free_mem(struct module *mod, void *start, void *end); 223 #else 224 static inline void ftrace_free_init_mem(void) 225 { 226 ftrace_boot_snapshot(); 227 } 228 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 229 #endif 230 231 /* 232 * Note, ftrace_ops can be referenced outside of RCU protection, unless 233 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel 234 * core data, the unregistering of it will perform a scheduling on all CPUs 235 * to make sure that there are no more users. Depending on the load of the 236 * system that may take a bit of time. 237 * 238 * Any private data added must also take care not to be freed and if private 239 * data is added to a ftrace_ops that is in core code, the user of the 240 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 241 */ 242 struct ftrace_ops { 243 ftrace_func_t func; 244 struct ftrace_ops __rcu *next; 245 unsigned long flags; 246 void *private; 247 ftrace_func_t saved_func; 248 #ifdef CONFIG_DYNAMIC_FTRACE 249 struct ftrace_ops_hash local_hash; 250 struct ftrace_ops_hash *func_hash; 251 struct ftrace_ops_hash old_hash; 252 unsigned long trampoline; 253 unsigned long trampoline_size; 254 struct list_head list; 255 #endif 256 }; 257 258 extern struct ftrace_ops __rcu *ftrace_ops_list; 259 extern struct ftrace_ops ftrace_list_end; 260 261 /* 262 * Traverse the ftrace_ops_list, invoking all entries. The reason that we 263 * can use rcu_dereference_raw_check() is that elements removed from this list 264 * are simply leaked, so there is no need to interact with a grace-period 265 * mechanism. The rcu_dereference_raw_check() calls are needed to handle 266 * concurrent insertions into the ftrace_ops_list. 267 * 268 * Silly Alpha and silly pointer-speculation compiler optimizations! 269 */ 270 #define do_for_each_ftrace_op(op, list) \ 271 op = rcu_dereference_raw_check(list); \ 272 do 273 274 /* 275 * Optimized for just a single item in the list (as that is the normal case). 276 */ 277 #define while_for_each_ftrace_op(op) \ 278 while (likely(op = rcu_dereference_raw_check((op)->next)) && \ 279 unlikely((op) != &ftrace_list_end)) 280 281 /* 282 * Type of the current tracing. 283 */ 284 enum ftrace_tracing_type_t { 285 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 286 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 287 }; 288 289 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 290 extern enum ftrace_tracing_type_t ftrace_tracing_type; 291 292 /* 293 * The ftrace_ops must be a static and should also 294 * be read_mostly. These functions do modify read_mostly variables 295 * so use them sparely. Never free an ftrace_op or modify the 296 * next pointer after it has been registered. Even after unregistering 297 * it, the next pointer may still be used internally. 298 */ 299 int register_ftrace_function(struct ftrace_ops *ops); 300 int unregister_ftrace_function(struct ftrace_ops *ops); 301 302 extern void ftrace_stub(unsigned long a0, unsigned long a1, 303 struct ftrace_ops *op, struct ftrace_regs *fregs); 304 305 #else /* !CONFIG_FUNCTION_TRACER */ 306 /* 307 * (un)register_ftrace_function must be a macro since the ops parameter 308 * must not be evaluated. 309 */ 310 #define register_ftrace_function(ops) ({ 0; }) 311 #define unregister_ftrace_function(ops) ({ 0; }) 312 static inline void ftrace_kill(void) { } 313 static inline void ftrace_free_init_mem(void) { } 314 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 315 #endif /* CONFIG_FUNCTION_TRACER */ 316 317 struct ftrace_func_entry { 318 struct hlist_node hlist; 319 unsigned long ip; 320 unsigned long direct; /* for direct lookup only */ 321 }; 322 323 struct dyn_ftrace; 324 325 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 326 extern int ftrace_direct_func_count; 327 int register_ftrace_direct(unsigned long ip, unsigned long addr); 328 int unregister_ftrace_direct(unsigned long ip, unsigned long addr); 329 int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr); 330 struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr); 331 int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 332 struct dyn_ftrace *rec, 333 unsigned long old_addr, 334 unsigned long new_addr); 335 unsigned long ftrace_find_rec_direct(unsigned long ip); 336 int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); 337 int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); 338 int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); 339 340 #else 341 struct ftrace_ops; 342 # define ftrace_direct_func_count 0 343 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr) 344 { 345 return -ENOTSUPP; 346 } 347 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr) 348 { 349 return -ENOTSUPP; 350 } 351 static inline int modify_ftrace_direct(unsigned long ip, 352 unsigned long old_addr, unsigned long new_addr) 353 { 354 return -ENOTSUPP; 355 } 356 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) 357 { 358 return NULL; 359 } 360 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 361 struct dyn_ftrace *rec, 362 unsigned long old_addr, 363 unsigned long new_addr) 364 { 365 return -ENODEV; 366 } 367 static inline unsigned long ftrace_find_rec_direct(unsigned long ip) 368 { 369 return 0; 370 } 371 static inline int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 372 { 373 return -ENODEV; 374 } 375 static inline int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 376 { 377 return -ENODEV; 378 } 379 static inline int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 380 { 381 return -ENODEV; 382 } 383 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 384 385 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 386 /* 387 * This must be implemented by the architecture. 388 * It is the way the ftrace direct_ops helper, when called 389 * via ftrace (because there's other callbacks besides the 390 * direct call), can inform the architecture's trampoline that this 391 * routine has a direct caller, and what the caller is. 392 * 393 * For example, in x86, it returns the direct caller 394 * callback function via the regs->orig_ax parameter. 395 * Then in the ftrace trampoline, if this is set, it makes 396 * the return from the trampoline jump to the direct caller 397 * instead of going back to the function it just traced. 398 */ 399 static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, 400 unsigned long addr) { } 401 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 402 403 #ifdef CONFIG_STACK_TRACER 404 405 extern int stack_tracer_enabled; 406 407 int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer, 408 size_t *lenp, loff_t *ppos); 409 410 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 411 DECLARE_PER_CPU(int, disable_stack_tracer); 412 413 /** 414 * stack_tracer_disable - temporarily disable the stack tracer 415 * 416 * There's a few locations (namely in RCU) where stack tracing 417 * cannot be executed. This function is used to disable stack 418 * tracing during those critical sections. 419 * 420 * This function must be called with preemption or interrupts 421 * disabled and stack_tracer_enable() must be called shortly after 422 * while preemption or interrupts are still disabled. 423 */ 424 static inline void stack_tracer_disable(void) 425 { 426 /* Preemption or interrupts must be disabled */ 427 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 428 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 429 this_cpu_inc(disable_stack_tracer); 430 } 431 432 /** 433 * stack_tracer_enable - re-enable the stack tracer 434 * 435 * After stack_tracer_disable() is called, stack_tracer_enable() 436 * must be called shortly afterward. 437 */ 438 static inline void stack_tracer_enable(void) 439 { 440 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 441 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 442 this_cpu_dec(disable_stack_tracer); 443 } 444 #else 445 static inline void stack_tracer_disable(void) { } 446 static inline void stack_tracer_enable(void) { } 447 #endif 448 449 #ifdef CONFIG_DYNAMIC_FTRACE 450 451 int ftrace_arch_code_modify_prepare(void); 452 int ftrace_arch_code_modify_post_process(void); 453 454 enum ftrace_bug_type { 455 FTRACE_BUG_UNKNOWN, 456 FTRACE_BUG_INIT, 457 FTRACE_BUG_NOP, 458 FTRACE_BUG_CALL, 459 FTRACE_BUG_UPDATE, 460 }; 461 extern enum ftrace_bug_type ftrace_bug_type; 462 463 /* 464 * Archs can set this to point to a variable that holds the value that was 465 * expected at the call site before calling ftrace_bug(). 466 */ 467 extern const void *ftrace_expected; 468 469 void ftrace_bug(int err, struct dyn_ftrace *rec); 470 471 struct seq_file; 472 473 extern int ftrace_text_reserved(const void *start, const void *end); 474 475 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); 476 477 bool is_ftrace_trampoline(unsigned long addr); 478 479 /* 480 * The dyn_ftrace record's flags field is split into two parts. 481 * the first part which is '0-FTRACE_REF_MAX' is a counter of 482 * the number of callbacks that have registered the function that 483 * the dyn_ftrace descriptor represents. 484 * 485 * The second part is a mask: 486 * ENABLED - the function is being traced 487 * REGS - the record wants the function to save regs 488 * REGS_EN - the function is set up to save regs. 489 * IPMODIFY - the record allows for the IP address to be changed. 490 * DISABLED - the record is not ready to be touched yet 491 * DIRECT - there is a direct function to call 492 * 493 * When a new ftrace_ops is registered and wants a function to save 494 * pt_regs, the rec->flags REGS is set. When the function has been 495 * set up to save regs, the REG_EN flag is set. Once a function 496 * starts saving regs it will do so until all ftrace_ops are removed 497 * from tracing that function. 498 */ 499 enum { 500 FTRACE_FL_ENABLED = (1UL << 31), 501 FTRACE_FL_REGS = (1UL << 30), 502 FTRACE_FL_REGS_EN = (1UL << 29), 503 FTRACE_FL_TRAMP = (1UL << 28), 504 FTRACE_FL_TRAMP_EN = (1UL << 27), 505 FTRACE_FL_IPMODIFY = (1UL << 26), 506 FTRACE_FL_DISABLED = (1UL << 25), 507 FTRACE_FL_DIRECT = (1UL << 24), 508 FTRACE_FL_DIRECT_EN = (1UL << 23), 509 }; 510 511 #define FTRACE_REF_MAX_SHIFT 23 512 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 513 514 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX) 515 516 struct dyn_ftrace { 517 unsigned long ip; /* address of mcount call-site */ 518 unsigned long flags; 519 struct dyn_arch_ftrace arch; 520 }; 521 522 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 523 int remove, int reset); 524 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, 525 unsigned int cnt, int remove, int reset); 526 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 527 int len, int reset); 528 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 529 int len, int reset); 530 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 531 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 532 void ftrace_free_filter(struct ftrace_ops *ops); 533 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 534 535 enum { 536 FTRACE_UPDATE_CALLS = (1 << 0), 537 FTRACE_DISABLE_CALLS = (1 << 1), 538 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 539 FTRACE_START_FUNC_RET = (1 << 3), 540 FTRACE_STOP_FUNC_RET = (1 << 4), 541 FTRACE_MAY_SLEEP = (1 << 5), 542 }; 543 544 /* 545 * The FTRACE_UPDATE_* enum is used to pass information back 546 * from the ftrace_update_record() and ftrace_test_record() 547 * functions. These are called by the code update routines 548 * to find out what is to be done for a given function. 549 * 550 * IGNORE - The function is already what we want it to be 551 * MAKE_CALL - Start tracing the function 552 * MODIFY_CALL - Stop saving regs for the function 553 * MAKE_NOP - Stop tracing the function 554 */ 555 enum { 556 FTRACE_UPDATE_IGNORE, 557 FTRACE_UPDATE_MAKE_CALL, 558 FTRACE_UPDATE_MODIFY_CALL, 559 FTRACE_UPDATE_MAKE_NOP, 560 }; 561 562 enum { 563 FTRACE_ITER_FILTER = (1 << 0), 564 FTRACE_ITER_NOTRACE = (1 << 1), 565 FTRACE_ITER_PRINTALL = (1 << 2), 566 FTRACE_ITER_DO_PROBES = (1 << 3), 567 FTRACE_ITER_PROBE = (1 << 4), 568 FTRACE_ITER_MOD = (1 << 5), 569 FTRACE_ITER_ENABLED = (1 << 6), 570 }; 571 572 void arch_ftrace_update_code(int command); 573 void arch_ftrace_update_trampoline(struct ftrace_ops *ops); 574 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec); 575 void arch_ftrace_trampoline_free(struct ftrace_ops *ops); 576 577 struct ftrace_rec_iter; 578 579 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 580 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 581 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 582 583 #define for_ftrace_rec_iter(iter) \ 584 for (iter = ftrace_rec_iter_start(); \ 585 iter; \ 586 iter = ftrace_rec_iter_next(iter)) 587 588 589 int ftrace_update_record(struct dyn_ftrace *rec, bool enable); 590 int ftrace_test_record(struct dyn_ftrace *rec, bool enable); 591 void ftrace_run_stop_machine(int command); 592 unsigned long ftrace_location(unsigned long ip); 593 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 594 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 595 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 596 597 extern ftrace_func_t ftrace_trace_function; 598 599 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 600 struct inode *inode, struct file *file); 601 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 602 size_t cnt, loff_t *ppos); 603 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 604 size_t cnt, loff_t *ppos); 605 int ftrace_regex_release(struct inode *inode, struct file *file); 606 607 void __init 608 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 609 610 /* defined in arch */ 611 extern int ftrace_ip_converted(unsigned long ip); 612 extern int ftrace_dyn_arch_init(void); 613 extern void ftrace_replace_code(int enable); 614 extern int ftrace_update_ftrace_func(ftrace_func_t func); 615 extern void ftrace_caller(void); 616 extern void ftrace_regs_caller(void); 617 extern void ftrace_call(void); 618 extern void ftrace_regs_call(void); 619 extern void mcount_call(void); 620 621 void ftrace_modify_all_code(int command); 622 623 #ifndef FTRACE_ADDR 624 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 625 #endif 626 627 #ifndef FTRACE_GRAPH_ADDR 628 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 629 #endif 630 631 #ifndef FTRACE_REGS_ADDR 632 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 633 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 634 #else 635 # define FTRACE_REGS_ADDR FTRACE_ADDR 636 #endif 637 #endif 638 639 /* 640 * If an arch would like functions that are only traced 641 * by the function graph tracer to jump directly to its own 642 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 643 * to be that address to jump to. 644 */ 645 #ifndef FTRACE_GRAPH_TRAMP_ADDR 646 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 647 #endif 648 649 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 650 extern void ftrace_graph_caller(void); 651 extern int ftrace_enable_ftrace_graph_caller(void); 652 extern int ftrace_disable_ftrace_graph_caller(void); 653 #else 654 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 655 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 656 #endif 657 658 /** 659 * ftrace_make_nop - convert code into nop 660 * @mod: module structure if called by module load initialization 661 * @rec: the call site record (e.g. mcount/fentry) 662 * @addr: the address that the call site should be calling 663 * 664 * This is a very sensitive operation and great care needs 665 * to be taken by the arch. The operation should carefully 666 * read the location, check to see if what is read is indeed 667 * what we expect it to be, and then on success of the compare, 668 * it should write to the location. 669 * 670 * The code segment at @rec->ip should be a caller to @addr 671 * 672 * Return must be: 673 * 0 on success 674 * -EFAULT on error reading the location 675 * -EINVAL on a failed compare of the contents 676 * -EPERM on error writing to the location 677 * Any other value will be considered a failure. 678 */ 679 extern int ftrace_make_nop(struct module *mod, 680 struct dyn_ftrace *rec, unsigned long addr); 681 682 /** 683 * ftrace_need_init_nop - return whether nop call sites should be initialized 684 * 685 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't 686 * need to call ftrace_init_nop() if the code is built with that flag. 687 * Architectures where this is not always the case may define their own 688 * condition. 689 * 690 * Return must be: 691 * 0 if ftrace_init_nop() should be called 692 * Nonzero if ftrace_init_nop() should not be called 693 */ 694 695 #ifndef ftrace_need_init_nop 696 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT)) 697 #endif 698 699 /** 700 * ftrace_init_nop - initialize a nop call site 701 * @mod: module structure if called by module load initialization 702 * @rec: the call site record (e.g. mcount/fentry) 703 * 704 * This is a very sensitive operation and great care needs 705 * to be taken by the arch. The operation should carefully 706 * read the location, check to see if what is read is indeed 707 * what we expect it to be, and then on success of the compare, 708 * it should write to the location. 709 * 710 * The code segment at @rec->ip should contain the contents created by 711 * the compiler 712 * 713 * Return must be: 714 * 0 on success 715 * -EFAULT on error reading the location 716 * -EINVAL on a failed compare of the contents 717 * -EPERM on error writing to the location 718 * Any other value will be considered a failure. 719 */ 720 #ifndef ftrace_init_nop 721 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) 722 { 723 return ftrace_make_nop(mod, rec, MCOUNT_ADDR); 724 } 725 #endif 726 727 /** 728 * ftrace_make_call - convert a nop call site into a call to addr 729 * @rec: the call site record (e.g. mcount/fentry) 730 * @addr: the address that the call site should call 731 * 732 * This is a very sensitive operation and great care needs 733 * to be taken by the arch. The operation should carefully 734 * read the location, check to see if what is read is indeed 735 * what we expect it to be, and then on success of the compare, 736 * it should write to the location. 737 * 738 * The code segment at @rec->ip should be a nop 739 * 740 * Return must be: 741 * 0 on success 742 * -EFAULT on error reading the location 743 * -EINVAL on a failed compare of the contents 744 * -EPERM on error writing to the location 745 * Any other value will be considered a failure. 746 */ 747 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 748 749 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 750 /** 751 * ftrace_modify_call - convert from one addr to another (no nop) 752 * @rec: the call site record (e.g. mcount/fentry) 753 * @old_addr: the address expected to be currently called to 754 * @addr: the address to change to 755 * 756 * This is a very sensitive operation and great care needs 757 * to be taken by the arch. The operation should carefully 758 * read the location, check to see if what is read is indeed 759 * what we expect it to be, and then on success of the compare, 760 * it should write to the location. 761 * 762 * The code segment at @rec->ip should be a caller to @old_addr 763 * 764 * Return must be: 765 * 0 on success 766 * -EFAULT on error reading the location 767 * -EINVAL on a failed compare of the contents 768 * -EPERM on error writing to the location 769 * Any other value will be considered a failure. 770 */ 771 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 772 unsigned long addr); 773 #else 774 /* Should never be called */ 775 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 776 unsigned long addr) 777 { 778 return -EINVAL; 779 } 780 #endif 781 782 /* May be defined in arch */ 783 extern int ftrace_arch_read_dyn_info(char *buf, int size); 784 785 extern int skip_trace(unsigned long ip); 786 extern void ftrace_module_init(struct module *mod); 787 extern void ftrace_module_enable(struct module *mod); 788 extern void ftrace_release_mod(struct module *mod); 789 790 extern void ftrace_disable_daemon(void); 791 extern void ftrace_enable_daemon(void); 792 #else /* CONFIG_DYNAMIC_FTRACE */ 793 static inline int skip_trace(unsigned long ip) { return 0; } 794 static inline void ftrace_disable_daemon(void) { } 795 static inline void ftrace_enable_daemon(void) { } 796 static inline void ftrace_module_init(struct module *mod) { } 797 static inline void ftrace_module_enable(struct module *mod) { } 798 static inline void ftrace_release_mod(struct module *mod) { } 799 static inline int ftrace_text_reserved(const void *start, const void *end) 800 { 801 return 0; 802 } 803 static inline unsigned long ftrace_location(unsigned long ip) 804 { 805 return 0; 806 } 807 808 /* 809 * Again users of functions that have ftrace_ops may not 810 * have them defined when ftrace is not enabled, but these 811 * functions may still be called. Use a macro instead of inline. 812 */ 813 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 814 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 815 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 816 #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; }) 817 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 818 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 819 #define ftrace_free_filter(ops) do { } while (0) 820 #define ftrace_ops_set_global_filter(ops) do { } while (0) 821 822 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 823 size_t cnt, loff_t *ppos) { return -ENODEV; } 824 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 825 size_t cnt, loff_t *ppos) { return -ENODEV; } 826 static inline int 827 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 828 829 static inline bool is_ftrace_trampoline(unsigned long addr) 830 { 831 return false; 832 } 833 #endif /* CONFIG_DYNAMIC_FTRACE */ 834 835 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 836 #ifndef ftrace_graph_func 837 #define ftrace_graph_func ftrace_stub 838 #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB 839 #else 840 #define FTRACE_OPS_GRAPH_STUB 0 841 #endif 842 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 843 844 /* totally disable ftrace - can not re-enable after this */ 845 void ftrace_kill(void); 846 847 static inline void tracer_disable(void) 848 { 849 #ifdef CONFIG_FUNCTION_TRACER 850 ftrace_enabled = 0; 851 #endif 852 } 853 854 /* 855 * Ftrace disable/restore without lock. Some synchronization mechanism 856 * must be used to prevent ftrace_enabled to be changed between 857 * disable/restore. 858 */ 859 static inline int __ftrace_enabled_save(void) 860 { 861 #ifdef CONFIG_FUNCTION_TRACER 862 int saved_ftrace_enabled = ftrace_enabled; 863 ftrace_enabled = 0; 864 return saved_ftrace_enabled; 865 #else 866 return 0; 867 #endif 868 } 869 870 static inline void __ftrace_enabled_restore(int enabled) 871 { 872 #ifdef CONFIG_FUNCTION_TRACER 873 ftrace_enabled = enabled; 874 #endif 875 } 876 877 /* All archs should have this, but we define it for consistency */ 878 #ifndef ftrace_return_address0 879 # define ftrace_return_address0 __builtin_return_address(0) 880 #endif 881 882 /* Archs may use other ways for ADDR1 and beyond */ 883 #ifndef ftrace_return_address 884 # ifdef CONFIG_FRAME_POINTER 885 # define ftrace_return_address(n) __builtin_return_address(n) 886 # else 887 # define ftrace_return_address(n) 0UL 888 # endif 889 #endif 890 891 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 892 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 893 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 894 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 895 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 896 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 897 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 898 899 static inline unsigned long get_lock_parent_ip(void) 900 { 901 unsigned long addr = CALLER_ADDR0; 902 903 if (!in_lock_functions(addr)) 904 return addr; 905 addr = CALLER_ADDR1; 906 if (!in_lock_functions(addr)) 907 return addr; 908 return CALLER_ADDR2; 909 } 910 911 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE 912 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 913 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 914 #else 915 /* 916 * Use defines instead of static inlines because some arches will make code out 917 * of the CALLER_ADDR, when we really want these to be a real nop. 918 */ 919 # define trace_preempt_on(a0, a1) do { } while (0) 920 # define trace_preempt_off(a0, a1) do { } while (0) 921 #endif 922 923 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 924 extern void ftrace_init(void); 925 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY 926 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries" 927 #else 928 #define FTRACE_CALLSITE_SECTION "__mcount_loc" 929 #endif 930 #else 931 static inline void ftrace_init(void) { } 932 #endif 933 934 /* 935 * Structure that defines an entry function trace. 936 * It's already packed but the attribute "packed" is needed 937 * to remove extra padding at the end. 938 */ 939 struct ftrace_graph_ent { 940 unsigned long func; /* Current function */ 941 int depth; 942 } __packed; 943 944 /* 945 * Structure that defines a return function trace. 946 * It's already packed but the attribute "packed" is needed 947 * to remove extra padding at the end. 948 */ 949 struct ftrace_graph_ret { 950 unsigned long func; /* Current function */ 951 int depth; 952 /* Number of functions that overran the depth limit for current task */ 953 unsigned int overrun; 954 unsigned long long calltime; 955 unsigned long long rettime; 956 } __packed; 957 958 /* Type of the callback handlers for tracing function graph*/ 959 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 960 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 961 962 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); 963 964 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 965 966 struct fgraph_ops { 967 trace_func_graph_ent_t entryfunc; 968 trace_func_graph_ret_t retfunc; 969 }; 970 971 /* 972 * Stack of return addresses for functions 973 * of a thread. 974 * Used in struct thread_info 975 */ 976 struct ftrace_ret_stack { 977 unsigned long ret; 978 unsigned long func; 979 unsigned long long calltime; 980 #ifdef CONFIG_FUNCTION_PROFILER 981 unsigned long long subtime; 982 #endif 983 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 984 unsigned long fp; 985 #endif 986 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 987 unsigned long *retp; 988 #endif 989 }; 990 991 /* 992 * Primary handler of a function return. 993 * It relays on ftrace_return_to_handler. 994 * Defined in entry_32/64.S 995 */ 996 extern void return_to_handler(void); 997 998 extern int 999 function_graph_enter(unsigned long ret, unsigned long func, 1000 unsigned long frame_pointer, unsigned long *retp); 1001 1002 struct ftrace_ret_stack * 1003 ftrace_graph_get_ret_stack(struct task_struct *task, int idx); 1004 1005 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 1006 unsigned long ret, unsigned long *retp); 1007 1008 /* 1009 * Sometimes we don't want to trace a function with the function 1010 * graph tracer but we want them to keep traced by the usual function 1011 * tracer if the function graph tracer is not configured. 1012 */ 1013 #define __notrace_funcgraph notrace 1014 1015 #define FTRACE_RETFUNC_DEPTH 50 1016 #define FTRACE_RETSTACK_ALLOC_SIZE 32 1017 1018 extern int register_ftrace_graph(struct fgraph_ops *ops); 1019 extern void unregister_ftrace_graph(struct fgraph_ops *ops); 1020 1021 extern bool ftrace_graph_is_dead(void); 1022 extern void ftrace_graph_stop(void); 1023 1024 /* The current handlers in use */ 1025 extern trace_func_graph_ret_t ftrace_graph_return; 1026 extern trace_func_graph_ent_t ftrace_graph_entry; 1027 1028 extern void ftrace_graph_init_task(struct task_struct *t); 1029 extern void ftrace_graph_exit_task(struct task_struct *t); 1030 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 1031 1032 static inline void pause_graph_tracing(void) 1033 { 1034 atomic_inc(¤t->tracing_graph_pause); 1035 } 1036 1037 static inline void unpause_graph_tracing(void) 1038 { 1039 atomic_dec(¤t->tracing_graph_pause); 1040 } 1041 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 1042 1043 #define __notrace_funcgraph 1044 1045 static inline void ftrace_graph_init_task(struct task_struct *t) { } 1046 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 1047 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 1048 1049 /* Define as macros as fgraph_ops may not be defined */ 1050 #define register_ftrace_graph(ops) ({ -1; }) 1051 #define unregister_ftrace_graph(ops) do { } while (0) 1052 1053 static inline unsigned long 1054 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 1055 unsigned long *retp) 1056 { 1057 return ret; 1058 } 1059 1060 static inline void pause_graph_tracing(void) { } 1061 static inline void unpause_graph_tracing(void) { } 1062 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 1063 1064 #ifdef CONFIG_TRACING 1065 1066 /* flags for current->trace */ 1067 enum { 1068 TSK_TRACE_FL_TRACE_BIT = 0, 1069 TSK_TRACE_FL_GRAPH_BIT = 1, 1070 }; 1071 enum { 1072 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 1073 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 1074 }; 1075 1076 static inline void set_tsk_trace_trace(struct task_struct *tsk) 1077 { 1078 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 1079 } 1080 1081 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 1082 { 1083 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 1084 } 1085 1086 static inline int test_tsk_trace_trace(struct task_struct *tsk) 1087 { 1088 return tsk->trace & TSK_TRACE_FL_TRACE; 1089 } 1090 1091 static inline void set_tsk_trace_graph(struct task_struct *tsk) 1092 { 1093 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 1094 } 1095 1096 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 1097 { 1098 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 1099 } 1100 1101 static inline int test_tsk_trace_graph(struct task_struct *tsk) 1102 { 1103 return tsk->trace & TSK_TRACE_FL_GRAPH; 1104 } 1105 1106 enum ftrace_dump_mode; 1107 1108 extern enum ftrace_dump_mode ftrace_dump_on_oops; 1109 extern int tracepoint_printk; 1110 1111 extern void disable_trace_on_warning(void); 1112 extern int __disable_trace_on_warning; 1113 1114 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 1115 void *buffer, size_t *lenp, loff_t *ppos); 1116 1117 #else /* CONFIG_TRACING */ 1118 static inline void disable_trace_on_warning(void) { } 1119 #endif /* CONFIG_TRACING */ 1120 1121 #ifdef CONFIG_FTRACE_SYSCALLS 1122 1123 unsigned long arch_syscall_addr(int nr); 1124 1125 #endif /* CONFIG_FTRACE_SYSCALLS */ 1126 1127 #endif /* _LINUX_FTRACE_H */ 1128