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