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 #ifdef CONFIG_FUNCTION_TRACER 45 /* 46 * If the arch's mcount caller does not support all of ftrace's 47 * features, then it must call an indirect function that 48 * does. Or at least does enough to prevent any unwelcome side effects. 49 * 50 * Also define the function prototype that these architectures use 51 * to call the ftrace_ops_list_func(). 52 */ 53 #if !ARCH_SUPPORTS_FTRACE_OPS 54 # define FTRACE_FORCE_LIST_FUNC 1 55 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); 56 #else 57 # define FTRACE_FORCE_LIST_FUNC 0 58 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, 59 struct ftrace_ops *op, struct ftrace_regs *fregs); 60 #endif 61 extern const struct ftrace_ops ftrace_nop_ops; 62 extern const struct ftrace_ops ftrace_list_ops; 63 struct ftrace_ops *ftrace_find_unique_ops(struct dyn_ftrace *rec); 64 #endif /* CONFIG_FUNCTION_TRACER */ 65 66 /* Main tracing buffer and events set up */ 67 #ifdef CONFIG_TRACING 68 void trace_init(void); 69 void early_trace_init(void); 70 #else 71 static inline void trace_init(void) { } 72 static inline void early_trace_init(void) { } 73 #endif 74 75 struct module; 76 struct ftrace_hash; 77 struct ftrace_direct_func; 78 79 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \ 80 defined(CONFIG_DYNAMIC_FTRACE) 81 const char * 82 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 83 unsigned long *off, char **modname, char *sym); 84 #else 85 static inline const char * 86 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 87 unsigned long *off, char **modname, char *sym) 88 { 89 return NULL; 90 } 91 #endif 92 93 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE) 94 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 95 char *type, char *name, 96 char *module_name, int *exported); 97 #else 98 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 99 char *type, char *name, 100 char *module_name, int *exported) 101 { 102 return -1; 103 } 104 #endif 105 106 #ifdef CONFIG_FUNCTION_TRACER 107 108 extern int ftrace_enabled; 109 110 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS 111 112 struct ftrace_regs { 113 struct pt_regs regs; 114 }; 115 #define arch_ftrace_get_regs(fregs) (&(fregs)->regs) 116 117 /* 118 * ftrace_regs_set_instruction_pointer() is to be defined by the architecture 119 * if to allow setting of the instruction pointer from the ftrace_regs when 120 * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching. 121 */ 122 #define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0) 123 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */ 124 125 static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs) 126 { 127 if (!fregs) 128 return NULL; 129 130 return arch_ftrace_get_regs(fregs); 131 } 132 133 /* 134 * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs. 135 * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs. 136 */ 137 static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs) 138 { 139 if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS)) 140 return true; 141 142 return ftrace_get_regs(fregs) != NULL; 143 } 144 145 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS 146 #define ftrace_regs_get_instruction_pointer(fregs) \ 147 instruction_pointer(ftrace_get_regs(fregs)) 148 #define ftrace_regs_get_argument(fregs, n) \ 149 regs_get_kernel_argument(ftrace_get_regs(fregs), n) 150 #define ftrace_regs_get_stack_pointer(fregs) \ 151 kernel_stack_pointer(ftrace_get_regs(fregs)) 152 #define ftrace_regs_return_value(fregs) \ 153 regs_return_value(ftrace_get_regs(fregs)) 154 #define ftrace_regs_set_return_value(fregs, ret) \ 155 regs_set_return_value(ftrace_get_regs(fregs), ret) 156 #define ftrace_override_function_with_return(fregs) \ 157 override_function_with_return(ftrace_get_regs(fregs)) 158 #define ftrace_regs_query_register_offset(name) \ 159 regs_query_register_offset(name) 160 #endif 161 162 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 163 struct ftrace_ops *op, struct ftrace_regs *fregs); 164 165 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 166 167 /* 168 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 169 * set in the flags member. 170 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and 171 * IPMODIFY are a kind of attribute flags which can be set only before 172 * registering the ftrace_ops, and can not be modified while registered. 173 * Changing those attribute flags after registering ftrace_ops will 174 * cause unexpected results. 175 * 176 * ENABLED - set/unset when ftrace_ops is registered/unregistered 177 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 178 * allocated ftrace_ops which need special care 179 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 180 * and passed to the callback. If this flag is set, but the 181 * architecture does not support passing regs 182 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 183 * ftrace_ops will fail to register, unless the next flag 184 * is set. 185 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 186 * handler can handle an arch that does not save regs 187 * (the handler tests if regs == NULL), then it can set 188 * this flag instead. It will not fail registering the ftrace_ops 189 * but, the regs field will be NULL if the arch does not support 190 * passing regs to the handler. 191 * Note, if this flag is set, the SAVE_REGS flag will automatically 192 * get set upon registering the ftrace_ops, if the arch supports it. 193 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure 194 * that the call back needs recursion protection. If it does 195 * not set this, then the ftrace infrastructure will assume 196 * that the callback can handle recursion on its own. 197 * STUB - The ftrace_ops is just a place holder. 198 * INITIALIZED - The ftrace_ops has already been initialized (first use time 199 * register_ftrace_function() is called, it will initialized the ops) 200 * DELETED - The ops are being deleted, do not let them be registered again. 201 * ADDING - The ops is in the process of being added. 202 * REMOVING - The ops is in the process of being removed. 203 * MODIFYING - The ops is in the process of changing its filter functions. 204 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 205 * The arch specific code sets this flag when it allocated a 206 * trampoline. This lets the arch know that it can update the 207 * trampoline in case the callback function changes. 208 * The ftrace_ops trampoline can be set by the ftrace users, and 209 * in such cases the arch must not modify it. Only the arch ftrace 210 * core code should set this flag. 211 * IPMODIFY - The ops can modify the IP register. This can only be set with 212 * SAVE_REGS. If another ops with this flag set is already registered 213 * for any of the functions that this ops will be registered for, then 214 * this ops will fail to register or set_filter_ip. 215 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 216 * RCU - Set when the ops can only be called when RCU is watching. 217 * TRACE_ARRAY - The ops->private points to a trace_array descriptor. 218 * PERMANENT - Set when the ops is permanent and should not be affected by 219 * ftrace_enabled. 220 * DIRECT - Used by the direct ftrace_ops helper for direct functions 221 * (internal ftrace only, should not be used by others) 222 */ 223 enum { 224 FTRACE_OPS_FL_ENABLED = BIT(0), 225 FTRACE_OPS_FL_DYNAMIC = BIT(1), 226 FTRACE_OPS_FL_SAVE_REGS = BIT(2), 227 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3), 228 FTRACE_OPS_FL_RECURSION = BIT(4), 229 FTRACE_OPS_FL_STUB = BIT(5), 230 FTRACE_OPS_FL_INITIALIZED = BIT(6), 231 FTRACE_OPS_FL_DELETED = BIT(7), 232 FTRACE_OPS_FL_ADDING = BIT(8), 233 FTRACE_OPS_FL_REMOVING = BIT(9), 234 FTRACE_OPS_FL_MODIFYING = BIT(10), 235 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11), 236 FTRACE_OPS_FL_IPMODIFY = BIT(12), 237 FTRACE_OPS_FL_PID = BIT(13), 238 FTRACE_OPS_FL_RCU = BIT(14), 239 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15), 240 FTRACE_OPS_FL_PERMANENT = BIT(16), 241 FTRACE_OPS_FL_DIRECT = BIT(17), 242 }; 243 244 /* 245 * FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes 246 * to a ftrace_ops. Note, the requests may fail. 247 * 248 * ENABLE_SHARE_IPMODIFY_SELF - enable a DIRECT ops to work on the same 249 * function as an ops with IPMODIFY. Called 250 * when the DIRECT ops is being registered. 251 * This is called with both direct_mutex and 252 * ftrace_lock are locked. 253 * 254 * ENABLE_SHARE_IPMODIFY_PEER - enable a DIRECT ops to work on the same 255 * function as an ops with IPMODIFY. Called 256 * when the other ops (the one with IPMODIFY) 257 * is being registered. 258 * This is called with direct_mutex locked. 259 * 260 * DISABLE_SHARE_IPMODIFY_PEER - disable a DIRECT ops to work on the same 261 * function as an ops with IPMODIFY. Called 262 * when the other ops (the one with IPMODIFY) 263 * is being unregistered. 264 * This is called with direct_mutex locked. 265 */ 266 enum ftrace_ops_cmd { 267 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF, 268 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER, 269 FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER, 270 }; 271 272 /* 273 * For most ftrace_ops_cmd, 274 * Returns: 275 * 0 - Success. 276 * Negative on failure. The return value is dependent on the 277 * callback. 278 */ 279 typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, enum ftrace_ops_cmd cmd); 280 281 #ifdef CONFIG_DYNAMIC_FTRACE 282 /* The hash used to know what functions callbacks trace */ 283 struct ftrace_ops_hash { 284 struct ftrace_hash __rcu *notrace_hash; 285 struct ftrace_hash __rcu *filter_hash; 286 struct mutex regex_lock; 287 }; 288 289 void ftrace_free_init_mem(void); 290 void ftrace_free_mem(struct module *mod, void *start, void *end); 291 #else 292 static inline void ftrace_free_init_mem(void) 293 { 294 ftrace_boot_snapshot(); 295 } 296 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 297 #endif 298 299 /* 300 * Note, ftrace_ops can be referenced outside of RCU protection, unless 301 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel 302 * core data, the unregistering of it will perform a scheduling on all CPUs 303 * to make sure that there are no more users. Depending on the load of the 304 * system that may take a bit of time. 305 * 306 * Any private data added must also take care not to be freed and if private 307 * data is added to a ftrace_ops that is in core code, the user of the 308 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 309 */ 310 struct ftrace_ops { 311 ftrace_func_t func; 312 struct ftrace_ops __rcu *next; 313 unsigned long flags; 314 void *private; 315 ftrace_func_t saved_func; 316 #ifdef CONFIG_DYNAMIC_FTRACE 317 struct ftrace_ops_hash local_hash; 318 struct ftrace_ops_hash *func_hash; 319 struct ftrace_ops_hash old_hash; 320 unsigned long trampoline; 321 unsigned long trampoline_size; 322 struct list_head list; 323 ftrace_ops_func_t ops_func; 324 #endif 325 }; 326 327 extern struct ftrace_ops __rcu *ftrace_ops_list; 328 extern struct ftrace_ops ftrace_list_end; 329 330 /* 331 * Traverse the ftrace_ops_list, invoking all entries. The reason that we 332 * can use rcu_dereference_raw_check() is that elements removed from this list 333 * are simply leaked, so there is no need to interact with a grace-period 334 * mechanism. The rcu_dereference_raw_check() calls are needed to handle 335 * concurrent insertions into the ftrace_ops_list. 336 * 337 * Silly Alpha and silly pointer-speculation compiler optimizations! 338 */ 339 #define do_for_each_ftrace_op(op, list) \ 340 op = rcu_dereference_raw_check(list); \ 341 do 342 343 /* 344 * Optimized for just a single item in the list (as that is the normal case). 345 */ 346 #define while_for_each_ftrace_op(op) \ 347 while (likely(op = rcu_dereference_raw_check((op)->next)) && \ 348 unlikely((op) != &ftrace_list_end)) 349 350 /* 351 * Type of the current tracing. 352 */ 353 enum ftrace_tracing_type_t { 354 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 355 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 356 }; 357 358 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 359 extern enum ftrace_tracing_type_t ftrace_tracing_type; 360 361 /* 362 * The ftrace_ops must be a static and should also 363 * be read_mostly. These functions do modify read_mostly variables 364 * so use them sparely. Never free an ftrace_op or modify the 365 * next pointer after it has been registered. Even after unregistering 366 * it, the next pointer may still be used internally. 367 */ 368 int register_ftrace_function(struct ftrace_ops *ops); 369 int unregister_ftrace_function(struct ftrace_ops *ops); 370 371 extern void ftrace_stub(unsigned long a0, unsigned long a1, 372 struct ftrace_ops *op, struct ftrace_regs *fregs); 373 374 375 int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs); 376 #else /* !CONFIG_FUNCTION_TRACER */ 377 /* 378 * (un)register_ftrace_function must be a macro since the ops parameter 379 * must not be evaluated. 380 */ 381 #define register_ftrace_function(ops) ({ 0; }) 382 #define unregister_ftrace_function(ops) ({ 0; }) 383 static inline void ftrace_kill(void) { } 384 static inline void ftrace_free_init_mem(void) { } 385 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 386 static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) 387 { 388 return -EOPNOTSUPP; 389 } 390 #endif /* CONFIG_FUNCTION_TRACER */ 391 392 struct ftrace_func_entry { 393 struct hlist_node hlist; 394 unsigned long ip; 395 unsigned long direct; /* for direct lookup only */ 396 }; 397 398 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 399 extern int ftrace_direct_func_count; 400 int register_ftrace_direct(unsigned long ip, unsigned long addr); 401 int unregister_ftrace_direct(unsigned long ip, unsigned long addr); 402 int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr); 403 struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr); 404 int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 405 struct dyn_ftrace *rec, 406 unsigned long old_addr, 407 unsigned long new_addr); 408 unsigned long ftrace_find_rec_direct(unsigned long ip); 409 int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); 410 int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); 411 int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); 412 int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr); 413 414 #else 415 struct ftrace_ops; 416 # define ftrace_direct_func_count 0 417 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr) 418 { 419 return -ENOTSUPP; 420 } 421 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr) 422 { 423 return -ENOTSUPP; 424 } 425 static inline int modify_ftrace_direct(unsigned long ip, 426 unsigned long old_addr, unsigned long new_addr) 427 { 428 return -ENOTSUPP; 429 } 430 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) 431 { 432 return NULL; 433 } 434 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 435 struct dyn_ftrace *rec, 436 unsigned long old_addr, 437 unsigned long new_addr) 438 { 439 return -ENODEV; 440 } 441 static inline unsigned long ftrace_find_rec_direct(unsigned long ip) 442 { 443 return 0; 444 } 445 static inline int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 446 { 447 return -ENODEV; 448 } 449 static inline int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 450 { 451 return -ENODEV; 452 } 453 static inline int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 454 { 455 return -ENODEV; 456 } 457 static inline int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr) 458 { 459 return -ENODEV; 460 } 461 462 /* 463 * This must be implemented by the architecture. 464 * It is the way the ftrace direct_ops helper, when called 465 * via ftrace (because there's other callbacks besides the 466 * direct call), can inform the architecture's trampoline that this 467 * routine has a direct caller, and what the caller is. 468 * 469 * For example, in x86, it returns the direct caller 470 * callback function via the regs->orig_ax parameter. 471 * Then in the ftrace trampoline, if this is set, it makes 472 * the return from the trampoline jump to the direct caller 473 * instead of going back to the function it just traced. 474 */ 475 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, 476 unsigned long addr) { } 477 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 478 479 #ifdef CONFIG_STACK_TRACER 480 481 extern int stack_tracer_enabled; 482 483 int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer, 484 size_t *lenp, loff_t *ppos); 485 486 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 487 DECLARE_PER_CPU(int, disable_stack_tracer); 488 489 /** 490 * stack_tracer_disable - temporarily disable the stack tracer 491 * 492 * There's a few locations (namely in RCU) where stack tracing 493 * cannot be executed. This function is used to disable stack 494 * tracing during those critical sections. 495 * 496 * This function must be called with preemption or interrupts 497 * disabled and stack_tracer_enable() must be called shortly after 498 * while preemption or interrupts are still disabled. 499 */ 500 static inline void stack_tracer_disable(void) 501 { 502 /* Preemption or interrupts must be disabled */ 503 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 504 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 505 this_cpu_inc(disable_stack_tracer); 506 } 507 508 /** 509 * stack_tracer_enable - re-enable the stack tracer 510 * 511 * After stack_tracer_disable() is called, stack_tracer_enable() 512 * must be called shortly afterward. 513 */ 514 static inline void stack_tracer_enable(void) 515 { 516 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 517 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 518 this_cpu_dec(disable_stack_tracer); 519 } 520 #else 521 static inline void stack_tracer_disable(void) { } 522 static inline void stack_tracer_enable(void) { } 523 #endif 524 525 #ifdef CONFIG_DYNAMIC_FTRACE 526 527 void ftrace_arch_code_modify_prepare(void); 528 void ftrace_arch_code_modify_post_process(void); 529 530 enum ftrace_bug_type { 531 FTRACE_BUG_UNKNOWN, 532 FTRACE_BUG_INIT, 533 FTRACE_BUG_NOP, 534 FTRACE_BUG_CALL, 535 FTRACE_BUG_UPDATE, 536 }; 537 extern enum ftrace_bug_type ftrace_bug_type; 538 539 /* 540 * Archs can set this to point to a variable that holds the value that was 541 * expected at the call site before calling ftrace_bug(). 542 */ 543 extern const void *ftrace_expected; 544 545 void ftrace_bug(int err, struct dyn_ftrace *rec); 546 547 struct seq_file; 548 549 extern int ftrace_text_reserved(const void *start, const void *end); 550 551 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); 552 553 bool is_ftrace_trampoline(unsigned long addr); 554 555 /* 556 * The dyn_ftrace record's flags field is split into two parts. 557 * the first part which is '0-FTRACE_REF_MAX' is a counter of 558 * the number of callbacks that have registered the function that 559 * the dyn_ftrace descriptor represents. 560 * 561 * The second part is a mask: 562 * ENABLED - the function is being traced 563 * REGS - the record wants the function to save regs 564 * REGS_EN - the function is set up to save regs. 565 * IPMODIFY - the record allows for the IP address to be changed. 566 * DISABLED - the record is not ready to be touched yet 567 * DIRECT - there is a direct function to call 568 * CALL_OPS - the record can use callsite-specific ops 569 * CALL_OPS_EN - the function is set up to use callsite-specific ops 570 * 571 * When a new ftrace_ops is registered and wants a function to save 572 * pt_regs, the rec->flags REGS is set. When the function has been 573 * set up to save regs, the REG_EN flag is set. Once a function 574 * starts saving regs it will do so until all ftrace_ops are removed 575 * from tracing that function. 576 */ 577 enum { 578 FTRACE_FL_ENABLED = (1UL << 31), 579 FTRACE_FL_REGS = (1UL << 30), 580 FTRACE_FL_REGS_EN = (1UL << 29), 581 FTRACE_FL_TRAMP = (1UL << 28), 582 FTRACE_FL_TRAMP_EN = (1UL << 27), 583 FTRACE_FL_IPMODIFY = (1UL << 26), 584 FTRACE_FL_DISABLED = (1UL << 25), 585 FTRACE_FL_DIRECT = (1UL << 24), 586 FTRACE_FL_DIRECT_EN = (1UL << 23), 587 FTRACE_FL_CALL_OPS = (1UL << 22), 588 FTRACE_FL_CALL_OPS_EN = (1UL << 21), 589 }; 590 591 #define FTRACE_REF_MAX_SHIFT 21 592 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 593 594 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX) 595 596 struct dyn_ftrace { 597 unsigned long ip; /* address of mcount call-site */ 598 unsigned long flags; 599 struct dyn_arch_ftrace arch; 600 }; 601 602 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 603 int remove, int reset); 604 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, 605 unsigned int cnt, int remove, int reset); 606 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 607 int len, int reset); 608 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 609 int len, int reset); 610 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 611 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 612 void ftrace_free_filter(struct ftrace_ops *ops); 613 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 614 615 enum { 616 FTRACE_UPDATE_CALLS = (1 << 0), 617 FTRACE_DISABLE_CALLS = (1 << 1), 618 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 619 FTRACE_START_FUNC_RET = (1 << 3), 620 FTRACE_STOP_FUNC_RET = (1 << 4), 621 FTRACE_MAY_SLEEP = (1 << 5), 622 }; 623 624 /* 625 * The FTRACE_UPDATE_* enum is used to pass information back 626 * from the ftrace_update_record() and ftrace_test_record() 627 * functions. These are called by the code update routines 628 * to find out what is to be done for a given function. 629 * 630 * IGNORE - The function is already what we want it to be 631 * MAKE_CALL - Start tracing the function 632 * MODIFY_CALL - Stop saving regs for the function 633 * MAKE_NOP - Stop tracing the function 634 */ 635 enum { 636 FTRACE_UPDATE_IGNORE, 637 FTRACE_UPDATE_MAKE_CALL, 638 FTRACE_UPDATE_MODIFY_CALL, 639 FTRACE_UPDATE_MAKE_NOP, 640 }; 641 642 enum { 643 FTRACE_ITER_FILTER = (1 << 0), 644 FTRACE_ITER_NOTRACE = (1 << 1), 645 FTRACE_ITER_PRINTALL = (1 << 2), 646 FTRACE_ITER_DO_PROBES = (1 << 3), 647 FTRACE_ITER_PROBE = (1 << 4), 648 FTRACE_ITER_MOD = (1 << 5), 649 FTRACE_ITER_ENABLED = (1 << 6), 650 }; 651 652 void arch_ftrace_update_code(int command); 653 void arch_ftrace_update_trampoline(struct ftrace_ops *ops); 654 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec); 655 void arch_ftrace_trampoline_free(struct ftrace_ops *ops); 656 657 struct ftrace_rec_iter; 658 659 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 660 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 661 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 662 663 #define for_ftrace_rec_iter(iter) \ 664 for (iter = ftrace_rec_iter_start(); \ 665 iter; \ 666 iter = ftrace_rec_iter_next(iter)) 667 668 669 int ftrace_update_record(struct dyn_ftrace *rec, bool enable); 670 int ftrace_test_record(struct dyn_ftrace *rec, bool enable); 671 void ftrace_run_stop_machine(int command); 672 unsigned long ftrace_location(unsigned long ip); 673 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 674 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 675 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 676 677 extern ftrace_func_t ftrace_trace_function; 678 679 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 680 struct inode *inode, struct file *file); 681 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 682 size_t cnt, loff_t *ppos); 683 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 684 size_t cnt, loff_t *ppos); 685 int ftrace_regex_release(struct inode *inode, struct file *file); 686 687 void __init 688 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 689 690 /* defined in arch */ 691 extern int ftrace_ip_converted(unsigned long ip); 692 extern int ftrace_dyn_arch_init(void); 693 extern void ftrace_replace_code(int enable); 694 extern int ftrace_update_ftrace_func(ftrace_func_t func); 695 extern void ftrace_caller(void); 696 extern void ftrace_regs_caller(void); 697 extern void ftrace_call(void); 698 extern void ftrace_regs_call(void); 699 extern void mcount_call(void); 700 701 void ftrace_modify_all_code(int command); 702 703 #ifndef FTRACE_ADDR 704 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 705 #endif 706 707 #ifndef FTRACE_GRAPH_ADDR 708 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 709 #endif 710 711 #ifndef FTRACE_REGS_ADDR 712 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 713 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 714 #else 715 # define FTRACE_REGS_ADDR FTRACE_ADDR 716 #endif 717 #endif 718 719 /* 720 * If an arch would like functions that are only traced 721 * by the function graph tracer to jump directly to its own 722 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 723 * to be that address to jump to. 724 */ 725 #ifndef FTRACE_GRAPH_TRAMP_ADDR 726 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 727 #endif 728 729 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 730 extern void ftrace_graph_caller(void); 731 extern int ftrace_enable_ftrace_graph_caller(void); 732 extern int ftrace_disable_ftrace_graph_caller(void); 733 #else 734 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 735 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 736 #endif 737 738 /** 739 * ftrace_make_nop - convert code into nop 740 * @mod: module structure if called by module load initialization 741 * @rec: the call site record (e.g. mcount/fentry) 742 * @addr: the address that the call site should be calling 743 * 744 * This is a very sensitive operation and great care needs 745 * to be taken by the arch. The operation should carefully 746 * read the location, check to see if what is read is indeed 747 * what we expect it to be, and then on success of the compare, 748 * it should write to the location. 749 * 750 * The code segment at @rec->ip should be a caller to @addr 751 * 752 * Return must be: 753 * 0 on success 754 * -EFAULT on error reading the location 755 * -EINVAL on a failed compare of the contents 756 * -EPERM on error writing to the location 757 * Any other value will be considered a failure. 758 */ 759 extern int ftrace_make_nop(struct module *mod, 760 struct dyn_ftrace *rec, unsigned long addr); 761 762 /** 763 * ftrace_need_init_nop - return whether nop call sites should be initialized 764 * 765 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't 766 * need to call ftrace_init_nop() if the code is built with that flag. 767 * Architectures where this is not always the case may define their own 768 * condition. 769 * 770 * Return must be: 771 * 0 if ftrace_init_nop() should be called 772 * Nonzero if ftrace_init_nop() should not be called 773 */ 774 775 #ifndef ftrace_need_init_nop 776 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT)) 777 #endif 778 779 /** 780 * ftrace_init_nop - initialize a nop call site 781 * @mod: module structure if called by module load initialization 782 * @rec: the call site record (e.g. mcount/fentry) 783 * 784 * This is a very sensitive operation and great care needs 785 * to be taken by the arch. The operation should carefully 786 * read the location, check to see if what is read is indeed 787 * what we expect it to be, and then on success of the compare, 788 * it should write to the location. 789 * 790 * The code segment at @rec->ip should contain the contents created by 791 * the compiler 792 * 793 * Return must be: 794 * 0 on success 795 * -EFAULT on error reading the location 796 * -EINVAL on a failed compare of the contents 797 * -EPERM on error writing to the location 798 * Any other value will be considered a failure. 799 */ 800 #ifndef ftrace_init_nop 801 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) 802 { 803 return ftrace_make_nop(mod, rec, MCOUNT_ADDR); 804 } 805 #endif 806 807 /** 808 * ftrace_make_call - convert a nop call site into a call to addr 809 * @rec: the call site record (e.g. mcount/fentry) 810 * @addr: the address that the call site should call 811 * 812 * This is a very sensitive operation and great care needs 813 * to be taken by the arch. The operation should carefully 814 * read the location, check to see if what is read is indeed 815 * what we expect it to be, and then on success of the compare, 816 * it should write to the location. 817 * 818 * The code segment at @rec->ip should be a nop 819 * 820 * Return must be: 821 * 0 on success 822 * -EFAULT on error reading the location 823 * -EINVAL on a failed compare of the contents 824 * -EPERM on error writing to the location 825 * Any other value will be considered a failure. 826 */ 827 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 828 829 #if defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) || \ 830 defined(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) 831 /** 832 * ftrace_modify_call - convert from one addr to another (no nop) 833 * @rec: the call site record (e.g. mcount/fentry) 834 * @old_addr: the address expected to be currently called to 835 * @addr: the address to change to 836 * 837 * This is a very sensitive operation and great care needs 838 * to be taken by the arch. The operation should carefully 839 * read the location, check to see if what is read is indeed 840 * what we expect it to be, and then on success of the compare, 841 * it should write to the location. 842 * 843 * When using call ops, this is called when the associated ops change, even 844 * when (addr == old_addr). 845 * 846 * The code segment at @rec->ip should be a caller to @old_addr 847 * 848 * Return must be: 849 * 0 on success 850 * -EFAULT on error reading the location 851 * -EINVAL on a failed compare of the contents 852 * -EPERM on error writing to the location 853 * Any other value will be considered a failure. 854 */ 855 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 856 unsigned long addr); 857 #else 858 /* Should never be called */ 859 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 860 unsigned long addr) 861 { 862 return -EINVAL; 863 } 864 #endif 865 866 /* May be defined in arch */ 867 extern int ftrace_arch_read_dyn_info(char *buf, int size); 868 869 extern int skip_trace(unsigned long ip); 870 extern void ftrace_module_init(struct module *mod); 871 extern void ftrace_module_enable(struct module *mod); 872 extern void ftrace_release_mod(struct module *mod); 873 874 extern void ftrace_disable_daemon(void); 875 extern void ftrace_enable_daemon(void); 876 #else /* CONFIG_DYNAMIC_FTRACE */ 877 static inline int skip_trace(unsigned long ip) { return 0; } 878 static inline void ftrace_disable_daemon(void) { } 879 static inline void ftrace_enable_daemon(void) { } 880 static inline void ftrace_module_init(struct module *mod) { } 881 static inline void ftrace_module_enable(struct module *mod) { } 882 static inline void ftrace_release_mod(struct module *mod) { } 883 static inline int ftrace_text_reserved(const void *start, const void *end) 884 { 885 return 0; 886 } 887 static inline unsigned long ftrace_location(unsigned long ip) 888 { 889 return 0; 890 } 891 892 /* 893 * Again users of functions that have ftrace_ops may not 894 * have them defined when ftrace is not enabled, but these 895 * functions may still be called. Use a macro instead of inline. 896 */ 897 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 898 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 899 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 900 #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; }) 901 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 902 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 903 #define ftrace_free_filter(ops) do { } while (0) 904 #define ftrace_ops_set_global_filter(ops) do { } while (0) 905 906 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 907 size_t cnt, loff_t *ppos) { return -ENODEV; } 908 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 909 size_t cnt, loff_t *ppos) { return -ENODEV; } 910 static inline int 911 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 912 913 static inline bool is_ftrace_trampoline(unsigned long addr) 914 { 915 return false; 916 } 917 #endif /* CONFIG_DYNAMIC_FTRACE */ 918 919 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 920 #ifndef ftrace_graph_func 921 #define ftrace_graph_func ftrace_stub 922 #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB 923 #else 924 #define FTRACE_OPS_GRAPH_STUB 0 925 #endif 926 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 927 928 /* totally disable ftrace - can not re-enable after this */ 929 void ftrace_kill(void); 930 931 static inline void tracer_disable(void) 932 { 933 #ifdef CONFIG_FUNCTION_TRACER 934 ftrace_enabled = 0; 935 #endif 936 } 937 938 /* 939 * Ftrace disable/restore without lock. Some synchronization mechanism 940 * must be used to prevent ftrace_enabled to be changed between 941 * disable/restore. 942 */ 943 static inline int __ftrace_enabled_save(void) 944 { 945 #ifdef CONFIG_FUNCTION_TRACER 946 int saved_ftrace_enabled = ftrace_enabled; 947 ftrace_enabled = 0; 948 return saved_ftrace_enabled; 949 #else 950 return 0; 951 #endif 952 } 953 954 static inline void __ftrace_enabled_restore(int enabled) 955 { 956 #ifdef CONFIG_FUNCTION_TRACER 957 ftrace_enabled = enabled; 958 #endif 959 } 960 961 /* All archs should have this, but we define it for consistency */ 962 #ifndef ftrace_return_address0 963 # define ftrace_return_address0 __builtin_return_address(0) 964 #endif 965 966 /* Archs may use other ways for ADDR1 and beyond */ 967 #ifndef ftrace_return_address 968 # ifdef CONFIG_FRAME_POINTER 969 # define ftrace_return_address(n) __builtin_return_address(n) 970 # else 971 # define ftrace_return_address(n) 0UL 972 # endif 973 #endif 974 975 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 976 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 977 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 978 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 979 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 980 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 981 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 982 983 static inline unsigned long get_lock_parent_ip(void) 984 { 985 unsigned long addr = CALLER_ADDR0; 986 987 if (!in_lock_functions(addr)) 988 return addr; 989 addr = CALLER_ADDR1; 990 if (!in_lock_functions(addr)) 991 return addr; 992 return CALLER_ADDR2; 993 } 994 995 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE 996 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 997 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 998 #else 999 /* 1000 * Use defines instead of static inlines because some arches will make code out 1001 * of the CALLER_ADDR, when we really want these to be a real nop. 1002 */ 1003 # define trace_preempt_on(a0, a1) do { } while (0) 1004 # define trace_preempt_off(a0, a1) do { } while (0) 1005 #endif 1006 1007 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 1008 extern void ftrace_init(void); 1009 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY 1010 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries" 1011 #else 1012 #define FTRACE_CALLSITE_SECTION "__mcount_loc" 1013 #endif 1014 #else 1015 static inline void ftrace_init(void) { } 1016 #endif 1017 1018 /* 1019 * Structure that defines an entry function trace. 1020 * It's already packed but the attribute "packed" is needed 1021 * to remove extra padding at the end. 1022 */ 1023 struct ftrace_graph_ent { 1024 unsigned long func; /* Current function */ 1025 int depth; 1026 } __packed; 1027 1028 /* 1029 * Structure that defines a return function trace. 1030 * It's already packed but the attribute "packed" is needed 1031 * to remove extra padding at the end. 1032 */ 1033 struct ftrace_graph_ret { 1034 unsigned long func; /* Current function */ 1035 int depth; 1036 /* Number of functions that overran the depth limit for current task */ 1037 unsigned int overrun; 1038 unsigned long long calltime; 1039 unsigned long long rettime; 1040 } __packed; 1041 1042 /* Type of the callback handlers for tracing function graph*/ 1043 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 1044 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 1045 1046 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); 1047 1048 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1049 1050 struct fgraph_ops { 1051 trace_func_graph_ent_t entryfunc; 1052 trace_func_graph_ret_t retfunc; 1053 }; 1054 1055 /* 1056 * Stack of return addresses for functions 1057 * of a thread. 1058 * Used in struct thread_info 1059 */ 1060 struct ftrace_ret_stack { 1061 unsigned long ret; 1062 unsigned long func; 1063 unsigned long long calltime; 1064 #ifdef CONFIG_FUNCTION_PROFILER 1065 unsigned long long subtime; 1066 #endif 1067 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 1068 unsigned long fp; 1069 #endif 1070 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 1071 unsigned long *retp; 1072 #endif 1073 }; 1074 1075 /* 1076 * Primary handler of a function return. 1077 * It relays on ftrace_return_to_handler. 1078 * Defined in entry_32/64.S 1079 */ 1080 extern void return_to_handler(void); 1081 1082 extern int 1083 function_graph_enter(unsigned long ret, unsigned long func, 1084 unsigned long frame_pointer, unsigned long *retp); 1085 1086 struct ftrace_ret_stack * 1087 ftrace_graph_get_ret_stack(struct task_struct *task, int idx); 1088 1089 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 1090 unsigned long ret, unsigned long *retp); 1091 1092 /* 1093 * Sometimes we don't want to trace a function with the function 1094 * graph tracer but we want them to keep traced by the usual function 1095 * tracer if the function graph tracer is not configured. 1096 */ 1097 #define __notrace_funcgraph notrace 1098 1099 #define FTRACE_RETFUNC_DEPTH 50 1100 #define FTRACE_RETSTACK_ALLOC_SIZE 32 1101 1102 extern int register_ftrace_graph(struct fgraph_ops *ops); 1103 extern void unregister_ftrace_graph(struct fgraph_ops *ops); 1104 1105 /** 1106 * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called 1107 * 1108 * ftrace_graph_stop() is called when a severe error is detected in 1109 * the function graph tracing. This function is called by the critical 1110 * paths of function graph to keep those paths from doing any more harm. 1111 */ 1112 DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph); 1113 1114 static inline bool ftrace_graph_is_dead(void) 1115 { 1116 return static_branch_unlikely(&kill_ftrace_graph); 1117 } 1118 1119 extern void ftrace_graph_stop(void); 1120 1121 /* The current handlers in use */ 1122 extern trace_func_graph_ret_t ftrace_graph_return; 1123 extern trace_func_graph_ent_t ftrace_graph_entry; 1124 1125 extern void ftrace_graph_init_task(struct task_struct *t); 1126 extern void ftrace_graph_exit_task(struct task_struct *t); 1127 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 1128 1129 static inline void pause_graph_tracing(void) 1130 { 1131 atomic_inc(¤t->tracing_graph_pause); 1132 } 1133 1134 static inline void unpause_graph_tracing(void) 1135 { 1136 atomic_dec(¤t->tracing_graph_pause); 1137 } 1138 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 1139 1140 #define __notrace_funcgraph 1141 1142 static inline void ftrace_graph_init_task(struct task_struct *t) { } 1143 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 1144 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 1145 1146 /* Define as macros as fgraph_ops may not be defined */ 1147 #define register_ftrace_graph(ops) ({ -1; }) 1148 #define unregister_ftrace_graph(ops) do { } while (0) 1149 1150 static inline unsigned long 1151 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 1152 unsigned long *retp) 1153 { 1154 return ret; 1155 } 1156 1157 static inline void pause_graph_tracing(void) { } 1158 static inline void unpause_graph_tracing(void) { } 1159 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 1160 1161 #ifdef CONFIG_TRACING 1162 enum ftrace_dump_mode; 1163 1164 extern enum ftrace_dump_mode ftrace_dump_on_oops; 1165 extern int tracepoint_printk; 1166 1167 extern void disable_trace_on_warning(void); 1168 extern int __disable_trace_on_warning; 1169 1170 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 1171 void *buffer, size_t *lenp, loff_t *ppos); 1172 1173 #else /* CONFIG_TRACING */ 1174 static inline void disable_trace_on_warning(void) { } 1175 #endif /* CONFIG_TRACING */ 1176 1177 #ifdef CONFIG_FTRACE_SYSCALLS 1178 1179 unsigned long arch_syscall_addr(int nr); 1180 1181 #endif /* CONFIG_FTRACE_SYSCALLS */ 1182 1183 #endif /* _LINUX_FTRACE_H */ 1184