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 extern struct ftrace_ops __rcu *ftrace_ops_list; 214 extern struct ftrace_ops ftrace_list_end; 215 216 /* 217 * Traverse the ftrace_global_list, invoking all entries. The reason that we 218 * can use rcu_dereference_raw_check() is that elements removed from this list 219 * are simply leaked, so there is no need to interact with a grace-period 220 * mechanism. The rcu_dereference_raw_check() calls are needed to handle 221 * concurrent insertions into the ftrace_global_list. 222 * 223 * Silly Alpha and silly pointer-speculation compiler optimizations! 224 */ 225 #define do_for_each_ftrace_op(op, list) \ 226 op = rcu_dereference_raw_check(list); \ 227 do 228 229 /* 230 * Optimized for just a single item in the list (as that is the normal case). 231 */ 232 #define while_for_each_ftrace_op(op) \ 233 while (likely(op = rcu_dereference_raw_check((op)->next)) && \ 234 unlikely((op) != &ftrace_list_end)) 235 236 /* 237 * Type of the current tracing. 238 */ 239 enum ftrace_tracing_type_t { 240 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 241 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 242 }; 243 244 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 245 extern enum ftrace_tracing_type_t ftrace_tracing_type; 246 247 /* 248 * The ftrace_ops must be a static and should also 249 * be read_mostly. These functions do modify read_mostly variables 250 * so use them sparely. Never free an ftrace_op or modify the 251 * next pointer after it has been registered. Even after unregistering 252 * it, the next pointer may still be used internally. 253 */ 254 int register_ftrace_function(struct ftrace_ops *ops); 255 int unregister_ftrace_function(struct ftrace_ops *ops); 256 257 extern void ftrace_stub(unsigned long a0, unsigned long a1, 258 struct ftrace_ops *op, struct pt_regs *regs); 259 260 #else /* !CONFIG_FUNCTION_TRACER */ 261 /* 262 * (un)register_ftrace_function must be a macro since the ops parameter 263 * must not be evaluated. 264 */ 265 #define register_ftrace_function(ops) ({ 0; }) 266 #define unregister_ftrace_function(ops) ({ 0; }) 267 static inline void ftrace_kill(void) { } 268 static inline void ftrace_free_init_mem(void) { } 269 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 270 #endif /* CONFIG_FUNCTION_TRACER */ 271 272 struct ftrace_func_entry { 273 struct hlist_node hlist; 274 unsigned long ip; 275 unsigned long direct; /* for direct lookup only */ 276 }; 277 278 struct dyn_ftrace; 279 280 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 281 extern int ftrace_direct_func_count; 282 int register_ftrace_direct(unsigned long ip, unsigned long addr); 283 int unregister_ftrace_direct(unsigned long ip, unsigned long addr); 284 int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr); 285 struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr); 286 int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 287 struct dyn_ftrace *rec, 288 unsigned long old_addr, 289 unsigned long new_addr); 290 unsigned long ftrace_find_rec_direct(unsigned long ip); 291 #else 292 # define ftrace_direct_func_count 0 293 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr) 294 { 295 return -ENOTSUPP; 296 } 297 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr) 298 { 299 return -ENOTSUPP; 300 } 301 static inline int modify_ftrace_direct(unsigned long ip, 302 unsigned long old_addr, unsigned long new_addr) 303 { 304 return -ENOTSUPP; 305 } 306 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) 307 { 308 return NULL; 309 } 310 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 311 struct dyn_ftrace *rec, 312 unsigned long old_addr, 313 unsigned long new_addr) 314 { 315 return -ENODEV; 316 } 317 static inline unsigned long ftrace_find_rec_direct(unsigned long ip) 318 { 319 return 0; 320 } 321 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 322 323 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 324 /* 325 * This must be implemented by the architecture. 326 * It is the way the ftrace direct_ops helper, when called 327 * via ftrace (because there's other callbacks besides the 328 * direct call), can inform the architecture's trampoline that this 329 * routine has a direct caller, and what the caller is. 330 * 331 * For example, in x86, it returns the direct caller 332 * callback function via the regs->orig_ax parameter. 333 * Then in the ftrace trampoline, if this is set, it makes 334 * the return from the trampoline jump to the direct caller 335 * instead of going back to the function it just traced. 336 */ 337 static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, 338 unsigned long addr) { } 339 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 340 341 #ifdef CONFIG_STACK_TRACER 342 343 extern int stack_tracer_enabled; 344 345 int stack_trace_sysctl(struct ctl_table *table, int write, 346 void __user *buffer, size_t *lenp, 347 loff_t *ppos); 348 349 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 350 DECLARE_PER_CPU(int, disable_stack_tracer); 351 352 /** 353 * stack_tracer_disable - temporarily disable the stack tracer 354 * 355 * There's a few locations (namely in RCU) where stack tracing 356 * cannot be executed. This function is used to disable stack 357 * tracing during those critical sections. 358 * 359 * This function must be called with preemption or interrupts 360 * disabled and stack_tracer_enable() must be called shortly after 361 * while preemption or interrupts are still disabled. 362 */ 363 static inline void stack_tracer_disable(void) 364 { 365 /* Preemption or interupts must be disabled */ 366 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 367 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 368 this_cpu_inc(disable_stack_tracer); 369 } 370 371 /** 372 * stack_tracer_enable - re-enable the stack tracer 373 * 374 * After stack_tracer_disable() is called, stack_tracer_enable() 375 * must be called shortly afterward. 376 */ 377 static inline void stack_tracer_enable(void) 378 { 379 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 380 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 381 this_cpu_dec(disable_stack_tracer); 382 } 383 #else 384 static inline void stack_tracer_disable(void) { } 385 static inline void stack_tracer_enable(void) { } 386 #endif 387 388 #ifdef CONFIG_DYNAMIC_FTRACE 389 390 int ftrace_arch_code_modify_prepare(void); 391 int ftrace_arch_code_modify_post_process(void); 392 393 enum ftrace_bug_type { 394 FTRACE_BUG_UNKNOWN, 395 FTRACE_BUG_INIT, 396 FTRACE_BUG_NOP, 397 FTRACE_BUG_CALL, 398 FTRACE_BUG_UPDATE, 399 }; 400 extern enum ftrace_bug_type ftrace_bug_type; 401 402 /* 403 * Archs can set this to point to a variable that holds the value that was 404 * expected at the call site before calling ftrace_bug(). 405 */ 406 extern const void *ftrace_expected; 407 408 void ftrace_bug(int err, struct dyn_ftrace *rec); 409 410 struct seq_file; 411 412 extern int ftrace_text_reserved(const void *start, const void *end); 413 414 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); 415 416 bool is_ftrace_trampoline(unsigned long addr); 417 418 /* 419 * The dyn_ftrace record's flags field is split into two parts. 420 * the first part which is '0-FTRACE_REF_MAX' is a counter of 421 * the number of callbacks that have registered the function that 422 * the dyn_ftrace descriptor represents. 423 * 424 * The second part is a mask: 425 * ENABLED - the function is being traced 426 * REGS - the record wants the function to save regs 427 * REGS_EN - the function is set up to save regs. 428 * IPMODIFY - the record allows for the IP address to be changed. 429 * DISABLED - the record is not ready to be touched yet 430 * DIRECT - there is a direct function to call 431 * 432 * When a new ftrace_ops is registered and wants a function to save 433 * pt_regs, the rec->flag REGS is set. When the function has been 434 * set up to save regs, the REG_EN flag is set. Once a function 435 * starts saving regs it will do so until all ftrace_ops are removed 436 * from tracing that function. 437 */ 438 enum { 439 FTRACE_FL_ENABLED = (1UL << 31), 440 FTRACE_FL_REGS = (1UL << 30), 441 FTRACE_FL_REGS_EN = (1UL << 29), 442 FTRACE_FL_TRAMP = (1UL << 28), 443 FTRACE_FL_TRAMP_EN = (1UL << 27), 444 FTRACE_FL_IPMODIFY = (1UL << 26), 445 FTRACE_FL_DISABLED = (1UL << 25), 446 FTRACE_FL_DIRECT = (1UL << 24), 447 FTRACE_FL_DIRECT_EN = (1UL << 23), 448 }; 449 450 #define FTRACE_REF_MAX_SHIFT 23 451 #define FTRACE_FL_BITS 9 452 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 453 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 454 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 455 456 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 457 458 struct dyn_ftrace { 459 unsigned long ip; /* address of mcount call-site */ 460 unsigned long flags; 461 struct dyn_arch_ftrace arch; 462 }; 463 464 int ftrace_force_update(void); 465 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 466 int remove, int reset); 467 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 468 int len, int reset); 469 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 470 int len, int reset); 471 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 472 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 473 void ftrace_free_filter(struct ftrace_ops *ops); 474 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 475 476 enum { 477 FTRACE_UPDATE_CALLS = (1 << 0), 478 FTRACE_DISABLE_CALLS = (1 << 1), 479 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 480 FTRACE_START_FUNC_RET = (1 << 3), 481 FTRACE_STOP_FUNC_RET = (1 << 4), 482 FTRACE_MAY_SLEEP = (1 << 5), 483 }; 484 485 /* 486 * The FTRACE_UPDATE_* enum is used to pass information back 487 * from the ftrace_update_record() and ftrace_test_record() 488 * functions. These are called by the code update routines 489 * to find out what is to be done for a given function. 490 * 491 * IGNORE - The function is already what we want it to be 492 * MAKE_CALL - Start tracing the function 493 * MODIFY_CALL - Stop saving regs for the function 494 * MAKE_NOP - Stop tracing the function 495 */ 496 enum { 497 FTRACE_UPDATE_IGNORE, 498 FTRACE_UPDATE_MAKE_CALL, 499 FTRACE_UPDATE_MODIFY_CALL, 500 FTRACE_UPDATE_MAKE_NOP, 501 }; 502 503 enum { 504 FTRACE_ITER_FILTER = (1 << 0), 505 FTRACE_ITER_NOTRACE = (1 << 1), 506 FTRACE_ITER_PRINTALL = (1 << 2), 507 FTRACE_ITER_DO_PROBES = (1 << 3), 508 FTRACE_ITER_PROBE = (1 << 4), 509 FTRACE_ITER_MOD = (1 << 5), 510 FTRACE_ITER_ENABLED = (1 << 6), 511 }; 512 513 void arch_ftrace_update_code(int command); 514 void arch_ftrace_update_trampoline(struct ftrace_ops *ops); 515 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec); 516 void arch_ftrace_trampoline_free(struct ftrace_ops *ops); 517 518 struct ftrace_rec_iter; 519 520 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 521 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 522 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 523 524 #define for_ftrace_rec_iter(iter) \ 525 for (iter = ftrace_rec_iter_start(); \ 526 iter; \ 527 iter = ftrace_rec_iter_next(iter)) 528 529 530 int ftrace_update_record(struct dyn_ftrace *rec, bool enable); 531 int ftrace_test_record(struct dyn_ftrace *rec, bool enable); 532 void ftrace_run_stop_machine(int command); 533 unsigned long ftrace_location(unsigned long ip); 534 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 535 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 536 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 537 538 extern ftrace_func_t ftrace_trace_function; 539 540 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 541 struct inode *inode, struct file *file); 542 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 543 size_t cnt, loff_t *ppos); 544 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 545 size_t cnt, loff_t *ppos); 546 int ftrace_regex_release(struct inode *inode, struct file *file); 547 548 void __init 549 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 550 551 /* defined in arch */ 552 extern int ftrace_ip_converted(unsigned long ip); 553 extern int ftrace_dyn_arch_init(void); 554 extern void ftrace_replace_code(int enable); 555 extern int ftrace_update_ftrace_func(ftrace_func_t func); 556 extern void ftrace_caller(void); 557 extern void ftrace_regs_caller(void); 558 extern void ftrace_call(void); 559 extern void ftrace_regs_call(void); 560 extern void mcount_call(void); 561 562 void ftrace_modify_all_code(int command); 563 564 #ifndef FTRACE_ADDR 565 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 566 #endif 567 568 #ifndef FTRACE_GRAPH_ADDR 569 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 570 #endif 571 572 #ifndef FTRACE_REGS_ADDR 573 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 574 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 575 #else 576 # define FTRACE_REGS_ADDR FTRACE_ADDR 577 #endif 578 #endif 579 580 /* 581 * If an arch would like functions that are only traced 582 * by the function graph tracer to jump directly to its own 583 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 584 * to be that address to jump to. 585 */ 586 #ifndef FTRACE_GRAPH_TRAMP_ADDR 587 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 588 #endif 589 590 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 591 extern void ftrace_graph_caller(void); 592 extern int ftrace_enable_ftrace_graph_caller(void); 593 extern int ftrace_disable_ftrace_graph_caller(void); 594 #else 595 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 596 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 597 #endif 598 599 /** 600 * ftrace_make_nop - convert code into nop 601 * @mod: module structure if called by module load initialization 602 * @rec: the call site record (e.g. mcount/fentry) 603 * @addr: the address that the call site should be calling 604 * 605 * This is a very sensitive operation and great care needs 606 * to be taken by the arch. The operation should carefully 607 * read the location, check to see if what is read is indeed 608 * what we expect it to be, and then on success of the compare, 609 * it should write to the location. 610 * 611 * The code segment at @rec->ip should be a caller to @addr 612 * 613 * Return must be: 614 * 0 on success 615 * -EFAULT on error reading the location 616 * -EINVAL on a failed compare of the contents 617 * -EPERM on error writing to the location 618 * Any other value will be considered a failure. 619 */ 620 extern int ftrace_make_nop(struct module *mod, 621 struct dyn_ftrace *rec, unsigned long addr); 622 623 624 /** 625 * ftrace_init_nop - initialize a nop call site 626 * @mod: module structure if called by module load initialization 627 * @rec: the call site record (e.g. mcount/fentry) 628 * 629 * This is a very sensitive operation and great care needs 630 * to be taken by the arch. The operation should carefully 631 * read the location, check to see if what is read is indeed 632 * what we expect it to be, and then on success of the compare, 633 * it should write to the location. 634 * 635 * The code segment at @rec->ip should contain the contents created by 636 * the compiler 637 * 638 * Return must be: 639 * 0 on success 640 * -EFAULT on error reading the location 641 * -EINVAL on a failed compare of the contents 642 * -EPERM on error writing to the location 643 * Any other value will be considered a failure. 644 */ 645 #ifndef ftrace_init_nop 646 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) 647 { 648 return ftrace_make_nop(mod, rec, MCOUNT_ADDR); 649 } 650 #endif 651 652 /** 653 * ftrace_make_call - convert a nop call site into a call to addr 654 * @rec: the call site record (e.g. mcount/fentry) 655 * @addr: the address that the call site should call 656 * 657 * This is a very sensitive operation and great care needs 658 * to be taken by the arch. The operation should carefully 659 * read the location, check to see if what is read is indeed 660 * what we expect it to be, and then on success of the compare, 661 * it should write to the location. 662 * 663 * The code segment at @rec->ip should be a nop 664 * 665 * Return must be: 666 * 0 on success 667 * -EFAULT on error reading the location 668 * -EINVAL on a failed compare of the contents 669 * -EPERM on error writing to the location 670 * Any other value will be considered a failure. 671 */ 672 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 673 674 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 675 /** 676 * ftrace_modify_call - convert from one addr to another (no nop) 677 * @rec: the call site record (e.g. mcount/fentry) 678 * @old_addr: the address expected to be currently called to 679 * @addr: the address to change to 680 * 681 * This is a very sensitive operation and great care needs 682 * to be taken by the arch. The operation should carefully 683 * read the location, check to see if what is read is indeed 684 * what we expect it to be, and then on success of the compare, 685 * it should write to the location. 686 * 687 * The code segment at @rec->ip should be a caller to @old_addr 688 * 689 * Return must be: 690 * 0 on success 691 * -EFAULT on error reading the location 692 * -EINVAL on a failed compare of the contents 693 * -EPERM on error writing to the location 694 * Any other value will be considered a failure. 695 */ 696 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 697 unsigned long addr); 698 #else 699 /* Should never be called */ 700 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 701 unsigned long addr) 702 { 703 return -EINVAL; 704 } 705 #endif 706 707 /* May be defined in arch */ 708 extern int ftrace_arch_read_dyn_info(char *buf, int size); 709 710 extern int skip_trace(unsigned long ip); 711 extern void ftrace_module_init(struct module *mod); 712 extern void ftrace_module_enable(struct module *mod); 713 extern void ftrace_release_mod(struct module *mod); 714 715 extern void ftrace_disable_daemon(void); 716 extern void ftrace_enable_daemon(void); 717 #else /* CONFIG_DYNAMIC_FTRACE */ 718 static inline int skip_trace(unsigned long ip) { return 0; } 719 static inline int ftrace_force_update(void) { return 0; } 720 static inline void ftrace_disable_daemon(void) { } 721 static inline void ftrace_enable_daemon(void) { } 722 static inline void ftrace_module_init(struct module *mod) { } 723 static inline void ftrace_module_enable(struct module *mod) { } 724 static inline void ftrace_release_mod(struct module *mod) { } 725 static inline int ftrace_text_reserved(const void *start, const void *end) 726 { 727 return 0; 728 } 729 static inline unsigned long ftrace_location(unsigned long ip) 730 { 731 return 0; 732 } 733 734 /* 735 * Again users of functions that have ftrace_ops may not 736 * have them defined when ftrace is not enabled, but these 737 * functions may still be called. Use a macro instead of inline. 738 */ 739 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 740 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 741 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 742 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 743 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 744 #define ftrace_free_filter(ops) do { } while (0) 745 #define ftrace_ops_set_global_filter(ops) do { } while (0) 746 747 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 748 size_t cnt, loff_t *ppos) { return -ENODEV; } 749 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 750 size_t cnt, loff_t *ppos) { return -ENODEV; } 751 static inline int 752 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 753 754 static inline bool is_ftrace_trampoline(unsigned long addr) 755 { 756 return false; 757 } 758 #endif /* CONFIG_DYNAMIC_FTRACE */ 759 760 /* totally disable ftrace - can not re-enable after this */ 761 void ftrace_kill(void); 762 763 static inline void tracer_disable(void) 764 { 765 #ifdef CONFIG_FUNCTION_TRACER 766 ftrace_enabled = 0; 767 #endif 768 } 769 770 /* 771 * Ftrace disable/restore without lock. Some synchronization mechanism 772 * must be used to prevent ftrace_enabled to be changed between 773 * disable/restore. 774 */ 775 static inline int __ftrace_enabled_save(void) 776 { 777 #ifdef CONFIG_FUNCTION_TRACER 778 int saved_ftrace_enabled = ftrace_enabled; 779 ftrace_enabled = 0; 780 return saved_ftrace_enabled; 781 #else 782 return 0; 783 #endif 784 } 785 786 static inline void __ftrace_enabled_restore(int enabled) 787 { 788 #ifdef CONFIG_FUNCTION_TRACER 789 ftrace_enabled = enabled; 790 #endif 791 } 792 793 /* All archs should have this, but we define it for consistency */ 794 #ifndef ftrace_return_address0 795 # define ftrace_return_address0 __builtin_return_address(0) 796 #endif 797 798 /* Archs may use other ways for ADDR1 and beyond */ 799 #ifndef ftrace_return_address 800 # ifdef CONFIG_FRAME_POINTER 801 # define ftrace_return_address(n) __builtin_return_address(n) 802 # else 803 # define ftrace_return_address(n) 0UL 804 # endif 805 #endif 806 807 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 808 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 809 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 810 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 811 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 812 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 813 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 814 815 static inline unsigned long get_lock_parent_ip(void) 816 { 817 unsigned long addr = CALLER_ADDR0; 818 819 if (!in_lock_functions(addr)) 820 return addr; 821 addr = CALLER_ADDR1; 822 if (!in_lock_functions(addr)) 823 return addr; 824 return CALLER_ADDR2; 825 } 826 827 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE 828 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 829 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 830 #else 831 /* 832 * Use defines instead of static inlines because some arches will make code out 833 * of the CALLER_ADDR, when we really want these to be a real nop. 834 */ 835 # define trace_preempt_on(a0, a1) do { } while (0) 836 # define trace_preempt_off(a0, a1) do { } while (0) 837 #endif 838 839 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 840 extern void ftrace_init(void); 841 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY 842 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries" 843 #else 844 #define FTRACE_CALLSITE_SECTION "__mcount_loc" 845 #endif 846 #else 847 static inline void ftrace_init(void) { } 848 #endif 849 850 /* 851 * Structure that defines an entry function trace. 852 * It's already packed but the attribute "packed" is needed 853 * to remove extra padding at the end. 854 */ 855 struct ftrace_graph_ent { 856 unsigned long func; /* Current function */ 857 int depth; 858 } __packed; 859 860 /* 861 * Structure that defines a return function trace. 862 * It's already packed but the attribute "packed" is needed 863 * to remove extra padding at the end. 864 */ 865 struct ftrace_graph_ret { 866 unsigned long func; /* Current function */ 867 /* Number of functions that overran the depth limit for current task */ 868 unsigned long overrun; 869 unsigned long long calltime; 870 unsigned long long rettime; 871 int depth; 872 } __packed; 873 874 /* Type of the callback handlers for tracing function graph*/ 875 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 876 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 877 878 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); 879 880 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 881 882 struct fgraph_ops { 883 trace_func_graph_ent_t entryfunc; 884 trace_func_graph_ret_t retfunc; 885 }; 886 887 /* 888 * Stack of return addresses for functions 889 * of a thread. 890 * Used in struct thread_info 891 */ 892 struct ftrace_ret_stack { 893 unsigned long ret; 894 unsigned long func; 895 unsigned long long calltime; 896 #ifdef CONFIG_FUNCTION_PROFILER 897 unsigned long long subtime; 898 #endif 899 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 900 unsigned long fp; 901 #endif 902 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 903 unsigned long *retp; 904 #endif 905 }; 906 907 /* 908 * Primary handler of a function return. 909 * It relays on ftrace_return_to_handler. 910 * Defined in entry_32/64.S 911 */ 912 extern void return_to_handler(void); 913 914 extern int 915 function_graph_enter(unsigned long ret, unsigned long func, 916 unsigned long frame_pointer, unsigned long *retp); 917 918 struct ftrace_ret_stack * 919 ftrace_graph_get_ret_stack(struct task_struct *task, int idx); 920 921 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 922 unsigned long ret, unsigned long *retp); 923 924 /* 925 * Sometimes we don't want to trace a function with the function 926 * graph tracer but we want them to keep traced by the usual function 927 * tracer if the function graph tracer is not configured. 928 */ 929 #define __notrace_funcgraph notrace 930 931 #define FTRACE_RETFUNC_DEPTH 50 932 #define FTRACE_RETSTACK_ALLOC_SIZE 32 933 934 extern int register_ftrace_graph(struct fgraph_ops *ops); 935 extern void unregister_ftrace_graph(struct fgraph_ops *ops); 936 937 extern bool ftrace_graph_is_dead(void); 938 extern void ftrace_graph_stop(void); 939 940 /* The current handlers in use */ 941 extern trace_func_graph_ret_t ftrace_graph_return; 942 extern trace_func_graph_ent_t ftrace_graph_entry; 943 944 extern void ftrace_graph_init_task(struct task_struct *t); 945 extern void ftrace_graph_exit_task(struct task_struct *t); 946 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 947 948 static inline void pause_graph_tracing(void) 949 { 950 atomic_inc(¤t->tracing_graph_pause); 951 } 952 953 static inline void unpause_graph_tracing(void) 954 { 955 atomic_dec(¤t->tracing_graph_pause); 956 } 957 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 958 959 #define __notrace_funcgraph 960 961 static inline void ftrace_graph_init_task(struct task_struct *t) { } 962 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 963 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 964 965 /* Define as macros as fgraph_ops may not be defined */ 966 #define register_ftrace_graph(ops) ({ -1; }) 967 #define unregister_ftrace_graph(ops) do { } while (0) 968 969 static inline unsigned long 970 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 971 unsigned long *retp) 972 { 973 return ret; 974 } 975 976 static inline void pause_graph_tracing(void) { } 977 static inline void unpause_graph_tracing(void) { } 978 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 979 980 #ifdef CONFIG_TRACING 981 982 /* flags for current->trace */ 983 enum { 984 TSK_TRACE_FL_TRACE_BIT = 0, 985 TSK_TRACE_FL_GRAPH_BIT = 1, 986 }; 987 enum { 988 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 989 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 990 }; 991 992 static inline void set_tsk_trace_trace(struct task_struct *tsk) 993 { 994 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 995 } 996 997 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 998 { 999 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 1000 } 1001 1002 static inline int test_tsk_trace_trace(struct task_struct *tsk) 1003 { 1004 return tsk->trace & TSK_TRACE_FL_TRACE; 1005 } 1006 1007 static inline void set_tsk_trace_graph(struct task_struct *tsk) 1008 { 1009 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 1010 } 1011 1012 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 1013 { 1014 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 1015 } 1016 1017 static inline int test_tsk_trace_graph(struct task_struct *tsk) 1018 { 1019 return tsk->trace & TSK_TRACE_FL_GRAPH; 1020 } 1021 1022 enum ftrace_dump_mode; 1023 1024 extern enum ftrace_dump_mode ftrace_dump_on_oops; 1025 extern int tracepoint_printk; 1026 1027 extern void disable_trace_on_warning(void); 1028 extern int __disable_trace_on_warning; 1029 1030 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 1031 void __user *buffer, size_t *lenp, 1032 loff_t *ppos); 1033 1034 #else /* CONFIG_TRACING */ 1035 static inline void disable_trace_on_warning(void) { } 1036 #endif /* CONFIG_TRACING */ 1037 1038 #ifdef CONFIG_FTRACE_SYSCALLS 1039 1040 unsigned long arch_syscall_addr(int nr); 1041 1042 #endif /* CONFIG_FTRACE_SYSCALLS */ 1043 1044 #endif /* _LINUX_FTRACE_H */ 1045