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/jump_label.h> 13 #include <linux/kallsyms.h> 14 #include <linux/linkage.h> 15 #include <linux/bitops.h> 16 #include <linux/ptrace.h> 17 #include <linux/ktime.h> 18 #include <linux/sched.h> 19 #include <linux/types.h> 20 #include <linux/init.h> 21 #include <linux/fs.h> 22 23 #include <asm/ftrace.h> 24 25 /* 26 * If the arch supports passing the variable contents of 27 * function_trace_op as the third parameter back from the 28 * mcount call, then the arch should define this as 1. 29 */ 30 #ifndef ARCH_SUPPORTS_FTRACE_OPS 31 #define ARCH_SUPPORTS_FTRACE_OPS 0 32 #endif 33 34 #ifdef CONFIG_TRACING 35 extern void ftrace_boot_snapshot(void); 36 #else 37 static inline void ftrace_boot_snapshot(void) { } 38 #endif 39 40 struct ftrace_ops; 41 struct ftrace_regs; 42 struct dyn_ftrace; 43 44 char *arch_ftrace_match_adjust(char *str, const char *search); 45 46 #ifdef CONFIG_HAVE_FUNCTION_GRAPH_RETVAL 47 struct fgraph_ret_regs; 48 unsigned long ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs); 49 #else 50 unsigned long ftrace_return_to_handler(unsigned long frame_pointer); 51 #endif 52 53 #ifdef CONFIG_FUNCTION_TRACER 54 /* 55 * If the arch's mcount caller does not support all of ftrace's 56 * features, then it must call an indirect function that 57 * does. Or at least does enough to prevent any unwelcome side effects. 58 * 59 * Also define the function prototype that these architectures use 60 * to call the ftrace_ops_list_func(). 61 */ 62 #if !ARCH_SUPPORTS_FTRACE_OPS 63 # define FTRACE_FORCE_LIST_FUNC 1 64 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); 65 #else 66 # define FTRACE_FORCE_LIST_FUNC 0 67 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, 68 struct ftrace_ops *op, struct ftrace_regs *fregs); 69 #endif 70 extern const struct ftrace_ops ftrace_nop_ops; 71 extern const struct ftrace_ops ftrace_list_ops; 72 struct ftrace_ops *ftrace_find_unique_ops(struct dyn_ftrace *rec); 73 #endif /* CONFIG_FUNCTION_TRACER */ 74 75 /* Main tracing buffer and events set up */ 76 #ifdef CONFIG_TRACING 77 void trace_init(void); 78 void early_trace_init(void); 79 #else 80 static inline void trace_init(void) { } 81 static inline void early_trace_init(void) { } 82 #endif 83 84 struct module; 85 struct ftrace_hash; 86 struct ftrace_direct_func; 87 88 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \ 89 defined(CONFIG_DYNAMIC_FTRACE) 90 const char * 91 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 92 unsigned long *off, char **modname, char *sym); 93 #else 94 static inline const char * 95 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 96 unsigned long *off, char **modname, char *sym) 97 { 98 return NULL; 99 } 100 #endif 101 102 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE) 103 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 104 char *type, char *name, 105 char *module_name, int *exported); 106 #else 107 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 108 char *type, char *name, 109 char *module_name, int *exported) 110 { 111 return -1; 112 } 113 #endif 114 115 #ifdef CONFIG_FUNCTION_TRACER 116 117 extern int ftrace_enabled; 118 119 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS 120 121 struct ftrace_regs { 122 struct pt_regs regs; 123 }; 124 #define arch_ftrace_get_regs(fregs) (&(fregs)->regs) 125 126 /* 127 * ftrace_regs_set_instruction_pointer() is to be defined by the architecture 128 * if to allow setting of the instruction pointer from the ftrace_regs when 129 * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching. 130 */ 131 #define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0) 132 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */ 133 134 static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs) 135 { 136 if (!fregs) 137 return NULL; 138 139 return arch_ftrace_get_regs(fregs); 140 } 141 142 /* 143 * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs. 144 * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs. 145 */ 146 static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs) 147 { 148 if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS)) 149 return true; 150 151 return ftrace_get_regs(fregs) != NULL; 152 } 153 154 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS 155 #define ftrace_regs_get_instruction_pointer(fregs) \ 156 instruction_pointer(ftrace_get_regs(fregs)) 157 #define ftrace_regs_get_argument(fregs, n) \ 158 regs_get_kernel_argument(ftrace_get_regs(fregs), n) 159 #define ftrace_regs_get_stack_pointer(fregs) \ 160 kernel_stack_pointer(ftrace_get_regs(fregs)) 161 #define ftrace_regs_return_value(fregs) \ 162 regs_return_value(ftrace_get_regs(fregs)) 163 #define ftrace_regs_set_return_value(fregs, ret) \ 164 regs_set_return_value(ftrace_get_regs(fregs), ret) 165 #define ftrace_override_function_with_return(fregs) \ 166 override_function_with_return(ftrace_get_regs(fregs)) 167 #define ftrace_regs_query_register_offset(name) \ 168 regs_query_register_offset(name) 169 #endif 170 171 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 172 struct ftrace_ops *op, struct ftrace_regs *fregs); 173 174 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 175 176 /* 177 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 178 * set in the flags member. 179 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and 180 * IPMODIFY are a kind of attribute flags which can be set only before 181 * registering the ftrace_ops, and can not be modified while registered. 182 * Changing those attribute flags after registering ftrace_ops will 183 * cause unexpected results. 184 * 185 * ENABLED - set/unset when ftrace_ops is registered/unregistered 186 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 187 * allocated ftrace_ops which need special care 188 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 189 * and passed to the callback. If this flag is set, but the 190 * architecture does not support passing regs 191 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 192 * ftrace_ops will fail to register, unless the next flag 193 * is set. 194 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 195 * handler can handle an arch that does not save regs 196 * (the handler tests if regs == NULL), then it can set 197 * this flag instead. It will not fail registering the ftrace_ops 198 * but, the regs field will be NULL if the arch does not support 199 * passing regs to the handler. 200 * Note, if this flag is set, the SAVE_REGS flag will automatically 201 * get set upon registering the ftrace_ops, if the arch supports it. 202 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure 203 * that the call back needs recursion protection. If it does 204 * not set this, then the ftrace infrastructure will assume 205 * that the callback can handle recursion on its own. 206 * STUB - The ftrace_ops is just a place holder. 207 * INITIALIZED - The ftrace_ops has already been initialized (first use time 208 * register_ftrace_function() is called, it will initialized the ops) 209 * DELETED - The ops are being deleted, do not let them be registered again. 210 * ADDING - The ops is in the process of being added. 211 * REMOVING - The ops is in the process of being removed. 212 * MODIFYING - The ops is in the process of changing its filter functions. 213 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 214 * The arch specific code sets this flag when it allocated a 215 * trampoline. This lets the arch know that it can update the 216 * trampoline in case the callback function changes. 217 * The ftrace_ops trampoline can be set by the ftrace users, and 218 * in such cases the arch must not modify it. Only the arch ftrace 219 * core code should set this flag. 220 * IPMODIFY - The ops can modify the IP register. This can only be set with 221 * SAVE_REGS. If another ops with this flag set is already registered 222 * for any of the functions that this ops will be registered for, then 223 * this ops will fail to register or set_filter_ip. 224 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 225 * RCU - Set when the ops can only be called when RCU is watching. 226 * TRACE_ARRAY - The ops->private points to a trace_array descriptor. 227 * PERMANENT - Set when the ops is permanent and should not be affected by 228 * ftrace_enabled. 229 * DIRECT - Used by the direct ftrace_ops helper for direct functions 230 * (internal ftrace only, should not be used by others) 231 */ 232 enum { 233 FTRACE_OPS_FL_ENABLED = BIT(0), 234 FTRACE_OPS_FL_DYNAMIC = BIT(1), 235 FTRACE_OPS_FL_SAVE_REGS = BIT(2), 236 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3), 237 FTRACE_OPS_FL_RECURSION = BIT(4), 238 FTRACE_OPS_FL_STUB = BIT(5), 239 FTRACE_OPS_FL_INITIALIZED = BIT(6), 240 FTRACE_OPS_FL_DELETED = BIT(7), 241 FTRACE_OPS_FL_ADDING = BIT(8), 242 FTRACE_OPS_FL_REMOVING = BIT(9), 243 FTRACE_OPS_FL_MODIFYING = BIT(10), 244 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11), 245 FTRACE_OPS_FL_IPMODIFY = BIT(12), 246 FTRACE_OPS_FL_PID = BIT(13), 247 FTRACE_OPS_FL_RCU = BIT(14), 248 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15), 249 FTRACE_OPS_FL_PERMANENT = BIT(16), 250 FTRACE_OPS_FL_DIRECT = BIT(17), 251 }; 252 253 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS 254 #define FTRACE_OPS_FL_SAVE_ARGS FTRACE_OPS_FL_SAVE_REGS 255 #else 256 #define FTRACE_OPS_FL_SAVE_ARGS 0 257 #endif 258 259 /* 260 * FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes 261 * to a ftrace_ops. Note, the requests may fail. 262 * 263 * ENABLE_SHARE_IPMODIFY_SELF - enable a DIRECT ops to work on the same 264 * function as an ops with IPMODIFY. Called 265 * when the DIRECT ops is being registered. 266 * This is called with both direct_mutex and 267 * ftrace_lock are locked. 268 * 269 * ENABLE_SHARE_IPMODIFY_PEER - enable a DIRECT ops to work on the same 270 * function as an ops with IPMODIFY. Called 271 * when the other ops (the one with IPMODIFY) 272 * is being registered. 273 * This is called with direct_mutex locked. 274 * 275 * DISABLE_SHARE_IPMODIFY_PEER - disable a DIRECT ops to work on the same 276 * function as an ops with IPMODIFY. Called 277 * when the other ops (the one with IPMODIFY) 278 * is being unregistered. 279 * This is called with direct_mutex locked. 280 */ 281 enum ftrace_ops_cmd { 282 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF, 283 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER, 284 FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER, 285 }; 286 287 /* 288 * For most ftrace_ops_cmd, 289 * Returns: 290 * 0 - Success. 291 * Negative on failure. The return value is dependent on the 292 * callback. 293 */ 294 typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, enum ftrace_ops_cmd cmd); 295 296 #ifdef CONFIG_DYNAMIC_FTRACE 297 /* The hash used to know what functions callbacks trace */ 298 struct ftrace_ops_hash { 299 struct ftrace_hash __rcu *notrace_hash; 300 struct ftrace_hash __rcu *filter_hash; 301 struct mutex regex_lock; 302 }; 303 304 void ftrace_free_init_mem(void); 305 void ftrace_free_mem(struct module *mod, void *start, void *end); 306 #else 307 static inline void ftrace_free_init_mem(void) 308 { 309 ftrace_boot_snapshot(); 310 } 311 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 312 #endif 313 314 /* 315 * Note, ftrace_ops can be referenced outside of RCU protection, unless 316 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel 317 * core data, the unregistering of it will perform a scheduling on all CPUs 318 * to make sure that there are no more users. Depending on the load of the 319 * system that may take a bit of time. 320 * 321 * Any private data added must also take care not to be freed and if private 322 * data is added to a ftrace_ops that is in core code, the user of the 323 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 324 */ 325 struct ftrace_ops { 326 ftrace_func_t func; 327 struct ftrace_ops __rcu *next; 328 unsigned long flags; 329 void *private; 330 ftrace_func_t saved_func; 331 #ifdef CONFIG_DYNAMIC_FTRACE 332 struct ftrace_ops_hash local_hash; 333 struct ftrace_ops_hash *func_hash; 334 struct ftrace_ops_hash old_hash; 335 unsigned long trampoline; 336 unsigned long trampoline_size; 337 struct list_head list; 338 ftrace_ops_func_t ops_func; 339 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 340 unsigned long direct_call; 341 #endif 342 #endif 343 }; 344 345 extern struct ftrace_ops __rcu *ftrace_ops_list; 346 extern struct ftrace_ops ftrace_list_end; 347 348 /* 349 * Traverse the ftrace_ops_list, invoking all entries. The reason that we 350 * can use rcu_dereference_raw_check() is that elements removed from this list 351 * are simply leaked, so there is no need to interact with a grace-period 352 * mechanism. The rcu_dereference_raw_check() calls are needed to handle 353 * concurrent insertions into the ftrace_ops_list. 354 * 355 * Silly Alpha and silly pointer-speculation compiler optimizations! 356 */ 357 #define do_for_each_ftrace_op(op, list) \ 358 op = rcu_dereference_raw_check(list); \ 359 do 360 361 /* 362 * Optimized for just a single item in the list (as that is the normal case). 363 */ 364 #define while_for_each_ftrace_op(op) \ 365 while (likely(op = rcu_dereference_raw_check((op)->next)) && \ 366 unlikely((op) != &ftrace_list_end)) 367 368 /* 369 * Type of the current tracing. 370 */ 371 enum ftrace_tracing_type_t { 372 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 373 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 374 }; 375 376 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 377 extern enum ftrace_tracing_type_t ftrace_tracing_type; 378 379 /* 380 * The ftrace_ops must be a static and should also 381 * be read_mostly. These functions do modify read_mostly variables 382 * so use them sparely. Never free an ftrace_op or modify the 383 * next pointer after it has been registered. Even after unregistering 384 * it, the next pointer may still be used internally. 385 */ 386 int register_ftrace_function(struct ftrace_ops *ops); 387 int unregister_ftrace_function(struct ftrace_ops *ops); 388 389 extern void ftrace_stub(unsigned long a0, unsigned long a1, 390 struct ftrace_ops *op, struct ftrace_regs *fregs); 391 392 393 int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs); 394 #else /* !CONFIG_FUNCTION_TRACER */ 395 /* 396 * (un)register_ftrace_function must be a macro since the ops parameter 397 * must not be evaluated. 398 */ 399 #define register_ftrace_function(ops) ({ 0; }) 400 #define unregister_ftrace_function(ops) ({ 0; }) 401 static inline void ftrace_kill(void) { } 402 static inline void ftrace_free_init_mem(void) { } 403 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 404 static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) 405 { 406 return -EOPNOTSUPP; 407 } 408 #endif /* CONFIG_FUNCTION_TRACER */ 409 410 struct ftrace_func_entry { 411 struct hlist_node hlist; 412 unsigned long ip; 413 unsigned long direct; /* for direct lookup only */ 414 }; 415 416 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 417 extern int ftrace_direct_func_count; 418 unsigned long ftrace_find_rec_direct(unsigned long ip); 419 int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr); 420 int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, 421 bool free_filters); 422 int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr); 423 int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr); 424 425 void ftrace_stub_direct_tramp(void); 426 427 #else 428 struct ftrace_ops; 429 # define ftrace_direct_func_count 0 430 static inline unsigned long ftrace_find_rec_direct(unsigned long ip) 431 { 432 return 0; 433 } 434 static inline int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) 435 { 436 return -ENODEV; 437 } 438 static inline int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, 439 bool free_filters) 440 { 441 return -ENODEV; 442 } 443 static inline int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) 444 { 445 return -ENODEV; 446 } 447 static inline int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr) 448 { 449 return -ENODEV; 450 } 451 452 /* 453 * This must be implemented by the architecture. 454 * It is the way the ftrace direct_ops helper, when called 455 * via ftrace (because there's other callbacks besides the 456 * direct call), can inform the architecture's trampoline that this 457 * routine has a direct caller, and what the caller is. 458 * 459 * For example, in x86, it returns the direct caller 460 * callback function via the regs->orig_ax parameter. 461 * Then in the ftrace trampoline, if this is set, it makes 462 * the return from the trampoline jump to the direct caller 463 * instead of going back to the function it just traced. 464 */ 465 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, 466 unsigned long addr) { } 467 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 468 469 #ifdef CONFIG_STACK_TRACER 470 471 extern int stack_tracer_enabled; 472 473 int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer, 474 size_t *lenp, loff_t *ppos); 475 476 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 477 DECLARE_PER_CPU(int, disable_stack_tracer); 478 479 /** 480 * stack_tracer_disable - temporarily disable the stack tracer 481 * 482 * There's a few locations (namely in RCU) where stack tracing 483 * cannot be executed. This function is used to disable stack 484 * tracing during those critical sections. 485 * 486 * This function must be called with preemption or interrupts 487 * disabled and stack_tracer_enable() must be called shortly after 488 * while preemption or interrupts are still disabled. 489 */ 490 static inline void stack_tracer_disable(void) 491 { 492 /* Preemption or interrupts must be disabled */ 493 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 494 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 495 this_cpu_inc(disable_stack_tracer); 496 } 497 498 /** 499 * stack_tracer_enable - re-enable the stack tracer 500 * 501 * After stack_tracer_disable() is called, stack_tracer_enable() 502 * must be called shortly afterward. 503 */ 504 static inline void stack_tracer_enable(void) 505 { 506 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 507 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 508 this_cpu_dec(disable_stack_tracer); 509 } 510 #else 511 static inline void stack_tracer_disable(void) { } 512 static inline void stack_tracer_enable(void) { } 513 #endif 514 515 #ifdef CONFIG_DYNAMIC_FTRACE 516 517 void ftrace_arch_code_modify_prepare(void); 518 void ftrace_arch_code_modify_post_process(void); 519 520 enum ftrace_bug_type { 521 FTRACE_BUG_UNKNOWN, 522 FTRACE_BUG_INIT, 523 FTRACE_BUG_NOP, 524 FTRACE_BUG_CALL, 525 FTRACE_BUG_UPDATE, 526 }; 527 extern enum ftrace_bug_type ftrace_bug_type; 528 529 /* 530 * Archs can set this to point to a variable that holds the value that was 531 * expected at the call site before calling ftrace_bug(). 532 */ 533 extern const void *ftrace_expected; 534 535 void ftrace_bug(int err, struct dyn_ftrace *rec); 536 537 struct seq_file; 538 539 extern int ftrace_text_reserved(const void *start, const void *end); 540 541 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); 542 543 bool is_ftrace_trampoline(unsigned long addr); 544 545 /* 546 * The dyn_ftrace record's flags field is split into two parts. 547 * the first part which is '0-FTRACE_REF_MAX' is a counter of 548 * the number of callbacks that have registered the function that 549 * the dyn_ftrace descriptor represents. 550 * 551 * The second part is a mask: 552 * ENABLED - the function is being traced 553 * REGS - the record wants the function to save regs 554 * REGS_EN - the function is set up to save regs. 555 * IPMODIFY - the record allows for the IP address to be changed. 556 * DISABLED - the record is not ready to be touched yet 557 * DIRECT - there is a direct function to call 558 * CALL_OPS - the record can use callsite-specific ops 559 * CALL_OPS_EN - the function is set up to use callsite-specific ops 560 * TOUCHED - A callback was added since boot up 561 * MODIFIED - The function had IPMODIFY or DIRECT attached to it 562 * 563 * When a new ftrace_ops is registered and wants a function to save 564 * pt_regs, the rec->flags REGS is set. When the function has been 565 * set up to save regs, the REG_EN flag is set. Once a function 566 * starts saving regs it will do so until all ftrace_ops are removed 567 * from tracing that function. 568 */ 569 enum { 570 FTRACE_FL_ENABLED = (1UL << 31), 571 FTRACE_FL_REGS = (1UL << 30), 572 FTRACE_FL_REGS_EN = (1UL << 29), 573 FTRACE_FL_TRAMP = (1UL << 28), 574 FTRACE_FL_TRAMP_EN = (1UL << 27), 575 FTRACE_FL_IPMODIFY = (1UL << 26), 576 FTRACE_FL_DISABLED = (1UL << 25), 577 FTRACE_FL_DIRECT = (1UL << 24), 578 FTRACE_FL_DIRECT_EN = (1UL << 23), 579 FTRACE_FL_CALL_OPS = (1UL << 22), 580 FTRACE_FL_CALL_OPS_EN = (1UL << 21), 581 FTRACE_FL_TOUCHED = (1UL << 20), 582 FTRACE_FL_MODIFIED = (1UL << 19), 583 }; 584 585 #define FTRACE_REF_MAX_SHIFT 19 586 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 587 588 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX) 589 590 struct dyn_ftrace { 591 unsigned long ip; /* address of mcount call-site */ 592 unsigned long flags; 593 struct dyn_arch_ftrace arch; 594 }; 595 596 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 597 int remove, int reset); 598 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, 599 unsigned int cnt, int remove, int reset); 600 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 601 int len, int reset); 602 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 603 int len, int reset); 604 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 605 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 606 void ftrace_free_filter(struct ftrace_ops *ops); 607 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 608 609 enum { 610 FTRACE_UPDATE_CALLS = (1 << 0), 611 FTRACE_DISABLE_CALLS = (1 << 1), 612 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 613 FTRACE_START_FUNC_RET = (1 << 3), 614 FTRACE_STOP_FUNC_RET = (1 << 4), 615 FTRACE_MAY_SLEEP = (1 << 5), 616 }; 617 618 /* 619 * The FTRACE_UPDATE_* enum is used to pass information back 620 * from the ftrace_update_record() and ftrace_test_record() 621 * functions. These are called by the code update routines 622 * to find out what is to be done for a given function. 623 * 624 * IGNORE - The function is already what we want it to be 625 * MAKE_CALL - Start tracing the function 626 * MODIFY_CALL - Stop saving regs for the function 627 * MAKE_NOP - Stop tracing the function 628 */ 629 enum { 630 FTRACE_UPDATE_IGNORE, 631 FTRACE_UPDATE_MAKE_CALL, 632 FTRACE_UPDATE_MODIFY_CALL, 633 FTRACE_UPDATE_MAKE_NOP, 634 }; 635 636 enum { 637 FTRACE_ITER_FILTER = (1 << 0), 638 FTRACE_ITER_NOTRACE = (1 << 1), 639 FTRACE_ITER_PRINTALL = (1 << 2), 640 FTRACE_ITER_DO_PROBES = (1 << 3), 641 FTRACE_ITER_PROBE = (1 << 4), 642 FTRACE_ITER_MOD = (1 << 5), 643 FTRACE_ITER_ENABLED = (1 << 6), 644 FTRACE_ITER_TOUCHED = (1 << 7), 645 FTRACE_ITER_ADDRS = (1 << 8), 646 }; 647 648 void arch_ftrace_update_code(int command); 649 void arch_ftrace_update_trampoline(struct ftrace_ops *ops); 650 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec); 651 void arch_ftrace_trampoline_free(struct ftrace_ops *ops); 652 653 struct ftrace_rec_iter; 654 655 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 656 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 657 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 658 659 #define for_ftrace_rec_iter(iter) \ 660 for (iter = ftrace_rec_iter_start(); \ 661 iter; \ 662 iter = ftrace_rec_iter_next(iter)) 663 664 665 int ftrace_update_record(struct dyn_ftrace *rec, bool enable); 666 int ftrace_test_record(struct dyn_ftrace *rec, bool enable); 667 void ftrace_run_stop_machine(int command); 668 unsigned long ftrace_location(unsigned long ip); 669 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 670 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 671 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 672 673 extern ftrace_func_t ftrace_trace_function; 674 675 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 676 struct inode *inode, struct file *file); 677 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 678 size_t cnt, loff_t *ppos); 679 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 680 size_t cnt, loff_t *ppos); 681 int ftrace_regex_release(struct inode *inode, struct file *file); 682 683 void __init 684 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 685 686 /* defined in arch */ 687 extern int ftrace_ip_converted(unsigned long ip); 688 extern int ftrace_dyn_arch_init(void); 689 extern void ftrace_replace_code(int enable); 690 extern int ftrace_update_ftrace_func(ftrace_func_t func); 691 extern void ftrace_caller(void); 692 extern void ftrace_regs_caller(void); 693 extern void ftrace_call(void); 694 extern void ftrace_regs_call(void); 695 extern void mcount_call(void); 696 697 void ftrace_modify_all_code(int command); 698 699 #ifndef FTRACE_ADDR 700 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 701 #endif 702 703 #ifndef FTRACE_GRAPH_ADDR 704 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 705 #endif 706 707 #ifndef FTRACE_REGS_ADDR 708 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 709 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 710 #else 711 # define FTRACE_REGS_ADDR FTRACE_ADDR 712 #endif 713 #endif 714 715 /* 716 * If an arch would like functions that are only traced 717 * by the function graph tracer to jump directly to its own 718 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 719 * to be that address to jump to. 720 */ 721 #ifndef FTRACE_GRAPH_TRAMP_ADDR 722 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 723 #endif 724 725 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 726 extern void ftrace_graph_caller(void); 727 extern int ftrace_enable_ftrace_graph_caller(void); 728 extern int ftrace_disable_ftrace_graph_caller(void); 729 #else 730 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 731 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 732 #endif 733 734 /** 735 * ftrace_make_nop - convert code into nop 736 * @mod: module structure if called by module load initialization 737 * @rec: the call site record (e.g. mcount/fentry) 738 * @addr: the address that the call site should be calling 739 * 740 * This is a very sensitive operation and great care needs 741 * to be taken by the arch. The operation should carefully 742 * read the location, check to see if what is read is indeed 743 * what we expect it to be, and then on success of the compare, 744 * it should write to the location. 745 * 746 * The code segment at @rec->ip should be a caller to @addr 747 * 748 * Return must be: 749 * 0 on success 750 * -EFAULT on error reading the location 751 * -EINVAL on a failed compare of the contents 752 * -EPERM on error writing to the location 753 * Any other value will be considered a failure. 754 */ 755 extern int ftrace_make_nop(struct module *mod, 756 struct dyn_ftrace *rec, unsigned long addr); 757 758 /** 759 * ftrace_need_init_nop - return whether nop call sites should be initialized 760 * 761 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't 762 * need to call ftrace_init_nop() if the code is built with that flag. 763 * Architectures where this is not always the case may define their own 764 * condition. 765 * 766 * Return must be: 767 * 0 if ftrace_init_nop() should be called 768 * Nonzero if ftrace_init_nop() should not be called 769 */ 770 771 #ifndef ftrace_need_init_nop 772 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT)) 773 #endif 774 775 /** 776 * ftrace_init_nop - initialize a nop call site 777 * @mod: module structure if called by module load initialization 778 * @rec: the call site record (e.g. mcount/fentry) 779 * 780 * This is a very sensitive operation and great care needs 781 * to be taken by the arch. The operation should carefully 782 * read the location, check to see if what is read is indeed 783 * what we expect it to be, and then on success of the compare, 784 * it should write to the location. 785 * 786 * The code segment at @rec->ip should contain the contents created by 787 * the compiler 788 * 789 * Return must be: 790 * 0 on success 791 * -EFAULT on error reading the location 792 * -EINVAL on a failed compare of the contents 793 * -EPERM on error writing to the location 794 * Any other value will be considered a failure. 795 */ 796 #ifndef ftrace_init_nop 797 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) 798 { 799 return ftrace_make_nop(mod, rec, MCOUNT_ADDR); 800 } 801 #endif 802 803 /** 804 * ftrace_make_call - convert a nop call site into a call to addr 805 * @rec: the call site record (e.g. mcount/fentry) 806 * @addr: the address that the call site should call 807 * 808 * This is a very sensitive operation and great care needs 809 * to be taken by the arch. The operation should carefully 810 * read the location, check to see if what is read is indeed 811 * what we expect it to be, and then on success of the compare, 812 * it should write to the location. 813 * 814 * The code segment at @rec->ip should be a nop 815 * 816 * Return must be: 817 * 0 on success 818 * -EFAULT on error reading the location 819 * -EINVAL on a failed compare of the contents 820 * -EPERM on error writing to the location 821 * Any other value will be considered a failure. 822 */ 823 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 824 825 #if defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) || \ 826 defined(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) 827 /** 828 * ftrace_modify_call - convert from one addr to another (no nop) 829 * @rec: the call site record (e.g. mcount/fentry) 830 * @old_addr: the address expected to be currently called to 831 * @addr: the address to change to 832 * 833 * This is a very sensitive operation and great care needs 834 * to be taken by the arch. The operation should carefully 835 * read the location, check to see if what is read is indeed 836 * what we expect it to be, and then on success of the compare, 837 * it should write to the location. 838 * 839 * When using call ops, this is called when the associated ops change, even 840 * when (addr == old_addr). 841 * 842 * The code segment at @rec->ip should be a caller to @old_addr 843 * 844 * Return must be: 845 * 0 on success 846 * -EFAULT on error reading the location 847 * -EINVAL on a failed compare of the contents 848 * -EPERM on error writing to the location 849 * Any other value will be considered a failure. 850 */ 851 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 852 unsigned long addr); 853 #else 854 /* Should never be called */ 855 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 856 unsigned long addr) 857 { 858 return -EINVAL; 859 } 860 #endif 861 862 /* May be defined in arch */ 863 extern int ftrace_arch_read_dyn_info(char *buf, int size); 864 865 extern int skip_trace(unsigned long ip); 866 extern void ftrace_module_init(struct module *mod); 867 extern void ftrace_module_enable(struct module *mod); 868 extern void ftrace_release_mod(struct module *mod); 869 870 extern void ftrace_disable_daemon(void); 871 extern void ftrace_enable_daemon(void); 872 #else /* CONFIG_DYNAMIC_FTRACE */ 873 static inline int skip_trace(unsigned long ip) { return 0; } 874 static inline void ftrace_disable_daemon(void) { } 875 static inline void ftrace_enable_daemon(void) { } 876 static inline void ftrace_module_init(struct module *mod) { } 877 static inline void ftrace_module_enable(struct module *mod) { } 878 static inline void ftrace_release_mod(struct module *mod) { } 879 static inline int ftrace_text_reserved(const void *start, const void *end) 880 { 881 return 0; 882 } 883 static inline unsigned long ftrace_location(unsigned long ip) 884 { 885 return 0; 886 } 887 888 /* 889 * Again users of functions that have ftrace_ops may not 890 * have them defined when ftrace is not enabled, but these 891 * functions may still be called. Use a macro instead of inline. 892 */ 893 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 894 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 895 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 896 #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; }) 897 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 898 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 899 #define ftrace_free_filter(ops) do { } while (0) 900 #define ftrace_ops_set_global_filter(ops) do { } while (0) 901 902 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 903 size_t cnt, loff_t *ppos) { return -ENODEV; } 904 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 905 size_t cnt, loff_t *ppos) { return -ENODEV; } 906 static inline int 907 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 908 909 static inline bool is_ftrace_trampoline(unsigned long addr) 910 { 911 return false; 912 } 913 #endif /* CONFIG_DYNAMIC_FTRACE */ 914 915 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 916 #ifndef ftrace_graph_func 917 #define ftrace_graph_func ftrace_stub 918 #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB 919 #else 920 #define FTRACE_OPS_GRAPH_STUB 0 921 #endif 922 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 923 924 /* totally disable ftrace - can not re-enable after this */ 925 void ftrace_kill(void); 926 927 static inline void tracer_disable(void) 928 { 929 #ifdef CONFIG_FUNCTION_TRACER 930 ftrace_enabled = 0; 931 #endif 932 } 933 934 /* 935 * Ftrace disable/restore without lock. Some synchronization mechanism 936 * must be used to prevent ftrace_enabled to be changed between 937 * disable/restore. 938 */ 939 static inline int __ftrace_enabled_save(void) 940 { 941 #ifdef CONFIG_FUNCTION_TRACER 942 int saved_ftrace_enabled = ftrace_enabled; 943 ftrace_enabled = 0; 944 return saved_ftrace_enabled; 945 #else 946 return 0; 947 #endif 948 } 949 950 static inline void __ftrace_enabled_restore(int enabled) 951 { 952 #ifdef CONFIG_FUNCTION_TRACER 953 ftrace_enabled = enabled; 954 #endif 955 } 956 957 /* All archs should have this, but we define it for consistency */ 958 #ifndef ftrace_return_address0 959 # define ftrace_return_address0 __builtin_return_address(0) 960 #endif 961 962 /* Archs may use other ways for ADDR1 and beyond */ 963 #ifndef ftrace_return_address 964 # ifdef CONFIG_FRAME_POINTER 965 # define ftrace_return_address(n) __builtin_return_address(n) 966 # else 967 # define ftrace_return_address(n) 0UL 968 # endif 969 #endif 970 971 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 972 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 973 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 974 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 975 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 976 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 977 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 978 979 static __always_inline unsigned long get_lock_parent_ip(void) 980 { 981 unsigned long addr = CALLER_ADDR0; 982 983 if (!in_lock_functions(addr)) 984 return addr; 985 addr = CALLER_ADDR1; 986 if (!in_lock_functions(addr)) 987 return addr; 988 return CALLER_ADDR2; 989 } 990 991 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE 992 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 993 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 994 #else 995 /* 996 * Use defines instead of static inlines because some arches will make code out 997 * of the CALLER_ADDR, when we really want these to be a real nop. 998 */ 999 # define trace_preempt_on(a0, a1) do { } while (0) 1000 # define trace_preempt_off(a0, a1) do { } while (0) 1001 #endif 1002 1003 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 1004 extern void ftrace_init(void); 1005 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY 1006 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries" 1007 #else 1008 #define FTRACE_CALLSITE_SECTION "__mcount_loc" 1009 #endif 1010 #else 1011 static inline void ftrace_init(void) { } 1012 #endif 1013 1014 /* 1015 * Structure that defines an entry function trace. 1016 * It's already packed but the attribute "packed" is needed 1017 * to remove extra padding at the end. 1018 */ 1019 struct ftrace_graph_ent { 1020 unsigned long func; /* Current function */ 1021 int depth; 1022 } __packed; 1023 1024 /* 1025 * Structure that defines a return function trace. 1026 * It's already packed but the attribute "packed" is needed 1027 * to remove extra padding at the end. 1028 */ 1029 struct ftrace_graph_ret { 1030 unsigned long func; /* Current function */ 1031 #ifdef CONFIG_FUNCTION_GRAPH_RETVAL 1032 unsigned long retval; 1033 #endif 1034 int depth; 1035 /* Number of functions that overran the depth limit for current task */ 1036 unsigned int overrun; 1037 unsigned long long calltime; 1038 unsigned long long rettime; 1039 } __packed; 1040 1041 /* Type of the callback handlers for tracing function graph*/ 1042 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 1043 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 1044 1045 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); 1046 1047 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1048 1049 struct fgraph_ops { 1050 trace_func_graph_ent_t entryfunc; 1051 trace_func_graph_ret_t retfunc; 1052 }; 1053 1054 /* 1055 * Stack of return addresses for functions 1056 * of a thread. 1057 * Used in struct thread_info 1058 */ 1059 struct ftrace_ret_stack { 1060 unsigned long ret; 1061 unsigned long func; 1062 unsigned long long calltime; 1063 #ifdef CONFIG_FUNCTION_PROFILER 1064 unsigned long long subtime; 1065 #endif 1066 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 1067 unsigned long fp; 1068 #endif 1069 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 1070 unsigned long *retp; 1071 #endif 1072 }; 1073 1074 /* 1075 * Primary handler of a function return. 1076 * It relays on ftrace_return_to_handler. 1077 * Defined in entry_32/64.S 1078 */ 1079 extern void return_to_handler(void); 1080 1081 extern int 1082 function_graph_enter(unsigned long ret, unsigned long func, 1083 unsigned long frame_pointer, unsigned long *retp); 1084 1085 struct ftrace_ret_stack * 1086 ftrace_graph_get_ret_stack(struct task_struct *task, int idx); 1087 1088 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 1089 unsigned long ret, unsigned long *retp); 1090 1091 /* 1092 * Sometimes we don't want to trace a function with the function 1093 * graph tracer but we want them to keep traced by the usual function 1094 * tracer if the function graph tracer is not configured. 1095 */ 1096 #define __notrace_funcgraph notrace 1097 1098 #define FTRACE_RETFUNC_DEPTH 50 1099 #define FTRACE_RETSTACK_ALLOC_SIZE 32 1100 1101 extern int register_ftrace_graph(struct fgraph_ops *ops); 1102 extern void unregister_ftrace_graph(struct fgraph_ops *ops); 1103 1104 /** 1105 * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called 1106 * 1107 * ftrace_graph_stop() is called when a severe error is detected in 1108 * the function graph tracing. This function is called by the critical 1109 * paths of function graph to keep those paths from doing any more harm. 1110 */ 1111 DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph); 1112 1113 static inline bool ftrace_graph_is_dead(void) 1114 { 1115 return static_branch_unlikely(&kill_ftrace_graph); 1116 } 1117 1118 extern void ftrace_graph_stop(void); 1119 1120 /* The current handlers in use */ 1121 extern trace_func_graph_ret_t ftrace_graph_return; 1122 extern trace_func_graph_ent_t ftrace_graph_entry; 1123 1124 extern void ftrace_graph_init_task(struct task_struct *t); 1125 extern void ftrace_graph_exit_task(struct task_struct *t); 1126 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 1127 1128 static inline void pause_graph_tracing(void) 1129 { 1130 atomic_inc(¤t->tracing_graph_pause); 1131 } 1132 1133 static inline void unpause_graph_tracing(void) 1134 { 1135 atomic_dec(¤t->tracing_graph_pause); 1136 } 1137 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 1138 1139 #define __notrace_funcgraph 1140 1141 static inline void ftrace_graph_init_task(struct task_struct *t) { } 1142 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 1143 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 1144 1145 /* Define as macros as fgraph_ops may not be defined */ 1146 #define register_ftrace_graph(ops) ({ -1; }) 1147 #define unregister_ftrace_graph(ops) do { } while (0) 1148 1149 static inline unsigned long 1150 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 1151 unsigned long *retp) 1152 { 1153 return ret; 1154 } 1155 1156 static inline void pause_graph_tracing(void) { } 1157 static inline void unpause_graph_tracing(void) { } 1158 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 1159 1160 #ifdef CONFIG_TRACING 1161 enum ftrace_dump_mode; 1162 1163 extern enum ftrace_dump_mode ftrace_dump_on_oops; 1164 extern int tracepoint_printk; 1165 1166 extern void disable_trace_on_warning(void); 1167 extern int __disable_trace_on_warning; 1168 1169 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 1170 void *buffer, size_t *lenp, loff_t *ppos); 1171 1172 #else /* CONFIG_TRACING */ 1173 static inline void disable_trace_on_warning(void) { } 1174 #endif /* CONFIG_TRACING */ 1175 1176 #ifdef CONFIG_FTRACE_SYSCALLS 1177 1178 unsigned long arch_syscall_addr(int nr); 1179 1180 #endif /* CONFIG_FTRACE_SYSCALLS */ 1181 1182 #endif /* _LINUX_FTRACE_H */ 1183