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 87 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \ 88 defined(CONFIG_DYNAMIC_FTRACE) 89 int 90 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 91 unsigned long *off, char **modname, char *sym); 92 #else 93 static inline int 94 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 95 unsigned long *off, char **modname, char *sym) 96 { 97 return 0; 98 } 99 #endif 100 101 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE) 102 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 103 char *type, char *name, 104 char *module_name, int *exported); 105 #else 106 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 107 char *type, char *name, 108 char *module_name, int *exported) 109 { 110 return -1; 111 } 112 #endif 113 114 #ifdef CONFIG_FUNCTION_TRACER 115 116 #include <linux/ftrace_regs.h> 117 118 extern int ftrace_enabled; 119 120 /** 121 * ftrace_regs - ftrace partial/optimal register set 122 * 123 * ftrace_regs represents a group of registers which is used at the 124 * function entry and exit. There are three types of registers. 125 * 126 * - Registers for passing the parameters to callee, including the stack 127 * pointer. (e.g. rcx, rdx, rdi, rsi, r8, r9 and rsp on x86_64) 128 * - Registers for passing the return values to caller. 129 * (e.g. rax and rdx on x86_64) 130 * - Registers for hooking the function call and return including the 131 * frame pointer (the frame pointer is architecture/config dependent) 132 * (e.g. rip, rbp and rsp for x86_64) 133 * 134 * Also, architecture dependent fields can be used for internal process. 135 * (e.g. orig_ax on x86_64) 136 * 137 * On the function entry, those registers will be restored except for 138 * the stack pointer, so that user can change the function parameters 139 * and instruction pointer (e.g. live patching.) 140 * On the function exit, only registers which is used for return values 141 * are restored. 142 * 143 * NOTE: user *must not* access regs directly, only do it via APIs, because 144 * the member can be changed according to the architecture. 145 * This is why the structure is empty here, so that nothing accesses 146 * the ftrace_regs directly. 147 */ 148 struct ftrace_regs { 149 /* Nothing to see here, use the accessor functions! */ 150 }; 151 152 #define ftrace_regs_size() sizeof(struct __arch_ftrace_regs) 153 154 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS 155 /* 156 * Architectures that define HAVE_DYNAMIC_FTRACE_WITH_ARGS must define their own 157 * arch_ftrace_get_regs() where it only returns pt_regs *if* it is fully 158 * populated. It should return NULL otherwise. 159 */ 160 static inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs) 161 { 162 return &arch_ftrace_regs(fregs)->regs; 163 } 164 165 /* 166 * ftrace_regs_set_instruction_pointer() is to be defined by the architecture 167 * if to allow setting of the instruction pointer from the ftrace_regs when 168 * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching. 169 */ 170 #define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0) 171 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */ 172 173 static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs) 174 { 175 if (!fregs) 176 return NULL; 177 178 return arch_ftrace_get_regs(fregs); 179 } 180 181 /* 182 * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs. 183 * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs. 184 */ 185 static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs) 186 { 187 if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS)) 188 return true; 189 190 return ftrace_get_regs(fregs) != NULL; 191 } 192 193 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 194 struct ftrace_ops *op, struct ftrace_regs *fregs); 195 196 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 197 198 /* 199 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 200 * set in the flags member. 201 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and 202 * IPMODIFY are a kind of attribute flags which can be set only before 203 * registering the ftrace_ops, and can not be modified while registered. 204 * Changing those attribute flags after registering ftrace_ops will 205 * cause unexpected results. 206 * 207 * ENABLED - set/unset when ftrace_ops is registered/unregistered 208 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 209 * allocated ftrace_ops which need special care 210 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 211 * and passed to the callback. If this flag is set, but the 212 * architecture does not support passing regs 213 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 214 * ftrace_ops will fail to register, unless the next flag 215 * is set. 216 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 217 * handler can handle an arch that does not save regs 218 * (the handler tests if regs == NULL), then it can set 219 * this flag instead. It will not fail registering the ftrace_ops 220 * but, the regs field will be NULL if the arch does not support 221 * passing regs to the handler. 222 * Note, if this flag is set, the SAVE_REGS flag will automatically 223 * get set upon registering the ftrace_ops, if the arch supports it. 224 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure 225 * that the call back needs recursion protection. If it does 226 * not set this, then the ftrace infrastructure will assume 227 * that the callback can handle recursion on its own. 228 * STUB - The ftrace_ops is just a place holder. 229 * INITIALIZED - The ftrace_ops has already been initialized (first use time 230 * register_ftrace_function() is called, it will initialized the ops) 231 * DELETED - The ops are being deleted, do not let them be registered again. 232 * ADDING - The ops is in the process of being added. 233 * REMOVING - The ops is in the process of being removed. 234 * MODIFYING - The ops is in the process of changing its filter functions. 235 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 236 * The arch specific code sets this flag when it allocated a 237 * trampoline. This lets the arch know that it can update the 238 * trampoline in case the callback function changes. 239 * The ftrace_ops trampoline can be set by the ftrace users, and 240 * in such cases the arch must not modify it. Only the arch ftrace 241 * core code should set this flag. 242 * IPMODIFY - The ops can modify the IP register. This can only be set with 243 * SAVE_REGS. If another ops with this flag set is already registered 244 * for any of the functions that this ops will be registered for, then 245 * this ops will fail to register or set_filter_ip. 246 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 247 * RCU - Set when the ops can only be called when RCU is watching. 248 * TRACE_ARRAY - The ops->private points to a trace_array descriptor. 249 * PERMANENT - Set when the ops is permanent and should not be affected by 250 * ftrace_enabled. 251 * DIRECT - Used by the direct ftrace_ops helper for direct functions 252 * (internal ftrace only, should not be used by others) 253 * SUBOP - Is controlled by another op in field managed. 254 */ 255 enum { 256 FTRACE_OPS_FL_ENABLED = BIT(0), 257 FTRACE_OPS_FL_DYNAMIC = BIT(1), 258 FTRACE_OPS_FL_SAVE_REGS = BIT(2), 259 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3), 260 FTRACE_OPS_FL_RECURSION = BIT(4), 261 FTRACE_OPS_FL_STUB = BIT(5), 262 FTRACE_OPS_FL_INITIALIZED = BIT(6), 263 FTRACE_OPS_FL_DELETED = BIT(7), 264 FTRACE_OPS_FL_ADDING = BIT(8), 265 FTRACE_OPS_FL_REMOVING = BIT(9), 266 FTRACE_OPS_FL_MODIFYING = BIT(10), 267 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11), 268 FTRACE_OPS_FL_IPMODIFY = BIT(12), 269 FTRACE_OPS_FL_PID = BIT(13), 270 FTRACE_OPS_FL_RCU = BIT(14), 271 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15), 272 FTRACE_OPS_FL_PERMANENT = BIT(16), 273 FTRACE_OPS_FL_DIRECT = BIT(17), 274 FTRACE_OPS_FL_SUBOP = BIT(18), 275 }; 276 277 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS 278 #define FTRACE_OPS_FL_SAVE_ARGS FTRACE_OPS_FL_SAVE_REGS 279 #else 280 #define FTRACE_OPS_FL_SAVE_ARGS 0 281 #endif 282 283 /* 284 * FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes 285 * to a ftrace_ops. Note, the requests may fail. 286 * 287 * ENABLE_SHARE_IPMODIFY_SELF - enable a DIRECT ops to work on the same 288 * function as an ops with IPMODIFY. Called 289 * when the DIRECT ops is being registered. 290 * This is called with both direct_mutex and 291 * ftrace_lock are locked. 292 * 293 * ENABLE_SHARE_IPMODIFY_PEER - enable a DIRECT ops to work on the same 294 * function as an ops with IPMODIFY. Called 295 * when the other ops (the one with IPMODIFY) 296 * is being registered. 297 * This is called with direct_mutex locked. 298 * 299 * DISABLE_SHARE_IPMODIFY_PEER - disable a DIRECT ops to work on the same 300 * function as an ops with IPMODIFY. Called 301 * when the other ops (the one with IPMODIFY) 302 * is being unregistered. 303 * This is called with direct_mutex locked. 304 */ 305 enum ftrace_ops_cmd { 306 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF, 307 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER, 308 FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER, 309 }; 310 311 /* 312 * For most ftrace_ops_cmd, 313 * Returns: 314 * 0 - Success. 315 * Negative on failure. The return value is dependent on the 316 * callback. 317 */ 318 typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, enum ftrace_ops_cmd cmd); 319 320 #ifdef CONFIG_DYNAMIC_FTRACE 321 /* The hash used to know what functions callbacks trace */ 322 struct ftrace_ops_hash { 323 struct ftrace_hash __rcu *notrace_hash; 324 struct ftrace_hash __rcu *filter_hash; 325 struct mutex regex_lock; 326 }; 327 328 void ftrace_free_init_mem(void); 329 void ftrace_free_mem(struct module *mod, void *start, void *end); 330 #else 331 static inline void ftrace_free_init_mem(void) 332 { 333 ftrace_boot_snapshot(); 334 } 335 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 336 #endif 337 338 /* 339 * Note, ftrace_ops can be referenced outside of RCU protection, unless 340 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel 341 * core data, the unregistering of it will perform a scheduling on all CPUs 342 * to make sure that there are no more users. Depending on the load of the 343 * system that may take a bit of time. 344 * 345 * Any private data added must also take care not to be freed and if private 346 * data is added to a ftrace_ops that is in core code, the user of the 347 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 348 */ 349 struct ftrace_ops { 350 ftrace_func_t func; 351 struct ftrace_ops __rcu *next; 352 unsigned long flags; 353 void *private; 354 ftrace_func_t saved_func; 355 #ifdef CONFIG_DYNAMIC_FTRACE 356 struct ftrace_ops_hash local_hash; 357 struct ftrace_ops_hash *func_hash; 358 struct ftrace_ops_hash old_hash; 359 unsigned long trampoline; 360 unsigned long trampoline_size; 361 struct list_head list; 362 struct list_head subop_list; 363 ftrace_ops_func_t ops_func; 364 struct ftrace_ops *managed; 365 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 366 unsigned long direct_call; 367 #endif 368 #endif 369 }; 370 371 extern struct ftrace_ops __rcu *ftrace_ops_list; 372 extern struct ftrace_ops ftrace_list_end; 373 374 /* 375 * Traverse the ftrace_ops_list, invoking all entries. The reason that we 376 * can use rcu_dereference_raw_check() is that elements removed from this list 377 * are simply leaked, so there is no need to interact with a grace-period 378 * mechanism. The rcu_dereference_raw_check() calls are needed to handle 379 * concurrent insertions into the ftrace_ops_list. 380 * 381 * Silly Alpha and silly pointer-speculation compiler optimizations! 382 */ 383 #define do_for_each_ftrace_op(op, list) \ 384 op = rcu_dereference_raw_check(list); \ 385 do 386 387 /* 388 * Optimized for just a single item in the list (as that is the normal case). 389 */ 390 #define while_for_each_ftrace_op(op) \ 391 while (likely(op = rcu_dereference_raw_check((op)->next)) && \ 392 unlikely((op) != &ftrace_list_end)) 393 394 /* 395 * Type of the current tracing. 396 */ 397 enum ftrace_tracing_type_t { 398 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 399 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 400 }; 401 402 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 403 extern enum ftrace_tracing_type_t ftrace_tracing_type; 404 405 /* 406 * The ftrace_ops must be a static and should also 407 * be read_mostly. These functions do modify read_mostly variables 408 * so use them sparely. Never free an ftrace_op or modify the 409 * next pointer after it has been registered. Even after unregistering 410 * it, the next pointer may still be used internally. 411 */ 412 int register_ftrace_function(struct ftrace_ops *ops); 413 int unregister_ftrace_function(struct ftrace_ops *ops); 414 415 extern void ftrace_stub(unsigned long a0, unsigned long a1, 416 struct ftrace_ops *op, struct ftrace_regs *fregs); 417 418 419 int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs); 420 #else /* !CONFIG_FUNCTION_TRACER */ 421 /* 422 * (un)register_ftrace_function must be a macro since the ops parameter 423 * must not be evaluated. 424 */ 425 #define register_ftrace_function(ops) ({ 0; }) 426 #define unregister_ftrace_function(ops) ({ 0; }) 427 static inline void ftrace_kill(void) { } 428 static inline void ftrace_free_init_mem(void) { } 429 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 430 static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) 431 { 432 return -EOPNOTSUPP; 433 } 434 #endif /* CONFIG_FUNCTION_TRACER */ 435 436 struct ftrace_func_entry { 437 struct hlist_node hlist; 438 unsigned long ip; 439 unsigned long direct; /* for direct lookup only */ 440 }; 441 442 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 443 unsigned long ftrace_find_rec_direct(unsigned long ip); 444 int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr); 445 int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, 446 bool free_filters); 447 int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr); 448 int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr); 449 450 void ftrace_stub_direct_tramp(void); 451 452 #else 453 struct ftrace_ops; 454 static inline unsigned long ftrace_find_rec_direct(unsigned long ip) 455 { 456 return 0; 457 } 458 static inline int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) 459 { 460 return -ENODEV; 461 } 462 static inline int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, 463 bool free_filters) 464 { 465 return -ENODEV; 466 } 467 static inline int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) 468 { 469 return -ENODEV; 470 } 471 static inline int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr) 472 { 473 return -ENODEV; 474 } 475 476 /* 477 * This must be implemented by the architecture. 478 * It is the way the ftrace direct_ops helper, when called 479 * via ftrace (because there's other callbacks besides the 480 * direct call), can inform the architecture's trampoline that this 481 * routine has a direct caller, and what the caller is. 482 * 483 * For example, in x86, it returns the direct caller 484 * callback function via the regs->orig_ax parameter. 485 * Then in the ftrace trampoline, if this is set, it makes 486 * the return from the trampoline jump to the direct caller 487 * instead of going back to the function it just traced. 488 */ 489 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, 490 unsigned long addr) { } 491 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ 492 493 #ifdef CONFIG_STACK_TRACER 494 495 extern int stack_tracer_enabled; 496 497 int stack_trace_sysctl(const struct ctl_table *table, int write, void *buffer, 498 size_t *lenp, loff_t *ppos); 499 500 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 501 DECLARE_PER_CPU(int, disable_stack_tracer); 502 503 /** 504 * stack_tracer_disable - temporarily disable the stack tracer 505 * 506 * There's a few locations (namely in RCU) where stack tracing 507 * cannot be executed. This function is used to disable stack 508 * tracing during those critical sections. 509 * 510 * This function must be called with preemption or interrupts 511 * disabled and stack_tracer_enable() must be called shortly after 512 * while preemption or interrupts are still disabled. 513 */ 514 static inline void stack_tracer_disable(void) 515 { 516 /* Preemption or interrupts must be disabled */ 517 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 518 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 519 this_cpu_inc(disable_stack_tracer); 520 } 521 522 /** 523 * stack_tracer_enable - re-enable the stack tracer 524 * 525 * After stack_tracer_disable() is called, stack_tracer_enable() 526 * must be called shortly afterward. 527 */ 528 static inline void stack_tracer_enable(void) 529 { 530 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 531 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 532 this_cpu_dec(disable_stack_tracer); 533 } 534 #else 535 static inline void stack_tracer_disable(void) { } 536 static inline void stack_tracer_enable(void) { } 537 #endif 538 539 enum { 540 FTRACE_UPDATE_CALLS = (1 << 0), 541 FTRACE_DISABLE_CALLS = (1 << 1), 542 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 543 FTRACE_START_FUNC_RET = (1 << 3), 544 FTRACE_STOP_FUNC_RET = (1 << 4), 545 FTRACE_MAY_SLEEP = (1 << 5), 546 }; 547 548 #ifdef CONFIG_DYNAMIC_FTRACE 549 550 void ftrace_arch_code_modify_prepare(void); 551 void ftrace_arch_code_modify_post_process(void); 552 553 enum ftrace_bug_type { 554 FTRACE_BUG_UNKNOWN, 555 FTRACE_BUG_INIT, 556 FTRACE_BUG_NOP, 557 FTRACE_BUG_CALL, 558 FTRACE_BUG_UPDATE, 559 }; 560 extern enum ftrace_bug_type ftrace_bug_type; 561 562 /* 563 * Archs can set this to point to a variable that holds the value that was 564 * expected at the call site before calling ftrace_bug(). 565 */ 566 extern const void *ftrace_expected; 567 568 void ftrace_bug(int err, struct dyn_ftrace *rec); 569 570 struct seq_file; 571 572 extern int ftrace_text_reserved(const void *start, const void *end); 573 574 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); 575 576 bool is_ftrace_trampoline(unsigned long addr); 577 578 /* 579 * The dyn_ftrace record's flags field is split into two parts. 580 * the first part which is '0-FTRACE_REF_MAX' is a counter of 581 * the number of callbacks that have registered the function that 582 * the dyn_ftrace descriptor represents. 583 * 584 * The second part is a mask: 585 * ENABLED - the function is being traced 586 * REGS - the record wants the function to save regs 587 * REGS_EN - the function is set up to save regs. 588 * IPMODIFY - the record allows for the IP address to be changed. 589 * DISABLED - the record is not ready to be touched yet 590 * DIRECT - there is a direct function to call 591 * CALL_OPS - the record can use callsite-specific ops 592 * CALL_OPS_EN - the function is set up to use callsite-specific ops 593 * TOUCHED - A callback was added since boot up 594 * MODIFIED - The function had IPMODIFY or DIRECT attached to it 595 * 596 * When a new ftrace_ops is registered and wants a function to save 597 * pt_regs, the rec->flags REGS is set. When the function has been 598 * set up to save regs, the REG_EN flag is set. Once a function 599 * starts saving regs it will do so until all ftrace_ops are removed 600 * from tracing that function. 601 */ 602 enum { 603 FTRACE_FL_ENABLED = (1UL << 31), 604 FTRACE_FL_REGS = (1UL << 30), 605 FTRACE_FL_REGS_EN = (1UL << 29), 606 FTRACE_FL_TRAMP = (1UL << 28), 607 FTRACE_FL_TRAMP_EN = (1UL << 27), 608 FTRACE_FL_IPMODIFY = (1UL << 26), 609 FTRACE_FL_DISABLED = (1UL << 25), 610 FTRACE_FL_DIRECT = (1UL << 24), 611 FTRACE_FL_DIRECT_EN = (1UL << 23), 612 FTRACE_FL_CALL_OPS = (1UL << 22), 613 FTRACE_FL_CALL_OPS_EN = (1UL << 21), 614 FTRACE_FL_TOUCHED = (1UL << 20), 615 FTRACE_FL_MODIFIED = (1UL << 19), 616 }; 617 618 #define FTRACE_REF_MAX_SHIFT 19 619 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 620 621 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX) 622 623 struct dyn_ftrace { 624 unsigned long ip; /* address of mcount call-site */ 625 unsigned long flags; 626 struct dyn_arch_ftrace arch; 627 }; 628 629 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 630 int remove, int reset); 631 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, 632 unsigned int cnt, int remove, int reset); 633 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 634 int len, int reset); 635 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 636 int len, int reset); 637 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 638 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 639 void ftrace_free_filter(struct ftrace_ops *ops); 640 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 641 642 /* 643 * The FTRACE_UPDATE_* enum is used to pass information back 644 * from the ftrace_update_record() and ftrace_test_record() 645 * functions. These are called by the code update routines 646 * to find out what is to be done for a given function. 647 * 648 * IGNORE - The function is already what we want it to be 649 * MAKE_CALL - Start tracing the function 650 * MODIFY_CALL - Stop saving regs for the function 651 * MAKE_NOP - Stop tracing the function 652 */ 653 enum { 654 FTRACE_UPDATE_IGNORE, 655 FTRACE_UPDATE_MAKE_CALL, 656 FTRACE_UPDATE_MODIFY_CALL, 657 FTRACE_UPDATE_MAKE_NOP, 658 }; 659 660 enum { 661 FTRACE_ITER_FILTER = (1 << 0), 662 FTRACE_ITER_NOTRACE = (1 << 1), 663 FTRACE_ITER_PRINTALL = (1 << 2), 664 FTRACE_ITER_DO_PROBES = (1 << 3), 665 FTRACE_ITER_PROBE = (1 << 4), 666 FTRACE_ITER_MOD = (1 << 5), 667 FTRACE_ITER_ENABLED = (1 << 6), 668 FTRACE_ITER_TOUCHED = (1 << 7), 669 FTRACE_ITER_ADDRS = (1 << 8), 670 }; 671 672 void arch_ftrace_update_code(int command); 673 void arch_ftrace_update_trampoline(struct ftrace_ops *ops); 674 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec); 675 void arch_ftrace_trampoline_free(struct ftrace_ops *ops); 676 677 struct ftrace_rec_iter; 678 679 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 680 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 681 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 682 683 #define for_ftrace_rec_iter(iter) \ 684 for (iter = ftrace_rec_iter_start(); \ 685 iter; \ 686 iter = ftrace_rec_iter_next(iter)) 687 688 689 int ftrace_update_record(struct dyn_ftrace *rec, bool enable); 690 int ftrace_test_record(struct dyn_ftrace *rec, bool enable); 691 void ftrace_run_stop_machine(int command); 692 unsigned long ftrace_location(unsigned long ip); 693 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 694 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 695 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 696 697 extern ftrace_func_t ftrace_trace_function; 698 699 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 700 struct inode *inode, struct file *file); 701 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 702 size_t cnt, loff_t *ppos); 703 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 704 size_t cnt, loff_t *ppos); 705 int ftrace_regex_release(struct inode *inode, struct file *file); 706 707 void __init 708 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 709 710 /* defined in arch */ 711 extern int ftrace_dyn_arch_init(void); 712 extern void ftrace_replace_code(int enable); 713 extern int ftrace_update_ftrace_func(ftrace_func_t func); 714 extern void ftrace_caller(void); 715 extern void ftrace_regs_caller(void); 716 extern void ftrace_call(void); 717 extern void ftrace_regs_call(void); 718 extern void mcount_call(void); 719 720 void ftrace_modify_all_code(int command); 721 722 #ifndef FTRACE_ADDR 723 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 724 #endif 725 726 #ifndef FTRACE_GRAPH_ADDR 727 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 728 #endif 729 730 #ifndef FTRACE_REGS_ADDR 731 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 732 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 733 #else 734 # define FTRACE_REGS_ADDR FTRACE_ADDR 735 #endif 736 #endif 737 738 /* 739 * If an arch would like functions that are only traced 740 * by the function graph tracer to jump directly to its own 741 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 742 * to be that address to jump to. 743 */ 744 #ifndef FTRACE_GRAPH_TRAMP_ADDR 745 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 746 #endif 747 748 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 749 extern void ftrace_graph_caller(void); 750 extern int ftrace_enable_ftrace_graph_caller(void); 751 extern int ftrace_disable_ftrace_graph_caller(void); 752 #else 753 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 754 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 755 #endif 756 757 /** 758 * ftrace_make_nop - convert code into nop 759 * @mod: module structure if called by module load initialization 760 * @rec: the call site record (e.g. mcount/fentry) 761 * @addr: the address that the call site should be calling 762 * 763 * This is a very sensitive operation and great care needs 764 * to be taken by the arch. The operation should carefully 765 * read the location, check to see if what is read is indeed 766 * what we expect it to be, and then on success of the compare, 767 * it should write to the location. 768 * 769 * The code segment at @rec->ip should be a caller to @addr 770 * 771 * Return must be: 772 * 0 on success 773 * -EFAULT on error reading the location 774 * -EINVAL on a failed compare of the contents 775 * -EPERM on error writing to the location 776 * Any other value will be considered a failure. 777 */ 778 extern int ftrace_make_nop(struct module *mod, 779 struct dyn_ftrace *rec, unsigned long addr); 780 781 /** 782 * ftrace_need_init_nop - return whether nop call sites should be initialized 783 * 784 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't 785 * need to call ftrace_init_nop() if the code is built with that flag. 786 * Architectures where this is not always the case may define their own 787 * condition. 788 * 789 * Return must be: 790 * 0 if ftrace_init_nop() should be called 791 * Nonzero if ftrace_init_nop() should not be called 792 */ 793 794 #ifndef ftrace_need_init_nop 795 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT)) 796 #endif 797 798 /** 799 * ftrace_init_nop - initialize a nop call site 800 * @mod: module structure if called by module load initialization 801 * @rec: the call site record (e.g. mcount/fentry) 802 * 803 * This is a very sensitive operation and great care needs 804 * to be taken by the arch. The operation should carefully 805 * read the location, check to see if what is read is indeed 806 * what we expect it to be, and then on success of the compare, 807 * it should write to the location. 808 * 809 * The code segment at @rec->ip should contain the contents created by 810 * the compiler 811 * 812 * Return must be: 813 * 0 on success 814 * -EFAULT on error reading the location 815 * -EINVAL on a failed compare of the contents 816 * -EPERM on error writing to the location 817 * Any other value will be considered a failure. 818 */ 819 #ifndef ftrace_init_nop 820 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) 821 { 822 return ftrace_make_nop(mod, rec, MCOUNT_ADDR); 823 } 824 #endif 825 826 /** 827 * ftrace_make_call - convert a nop call site into a call to addr 828 * @rec: the call site record (e.g. mcount/fentry) 829 * @addr: the address that the call site should call 830 * 831 * This is a very sensitive operation and great care needs 832 * to be taken by the arch. The operation should carefully 833 * read the location, check to see if what is read is indeed 834 * what we expect it to be, and then on success of the compare, 835 * it should write to the location. 836 * 837 * The code segment at @rec->ip should be a nop 838 * 839 * Return must be: 840 * 0 on success 841 * -EFAULT on error reading the location 842 * -EINVAL on a failed compare of the contents 843 * -EPERM on error writing to the location 844 * Any other value will be considered a failure. 845 */ 846 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 847 848 #if defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) || \ 849 defined(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) || \ 850 defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) 851 /** 852 * ftrace_modify_call - convert from one addr to another (no nop) 853 * @rec: the call site record (e.g. mcount/fentry) 854 * @old_addr: the address expected to be currently called to 855 * @addr: the address to change to 856 * 857 * This is a very sensitive operation and great care needs 858 * to be taken by the arch. The operation should carefully 859 * read the location, check to see if what is read is indeed 860 * what we expect it to be, and then on success of the compare, 861 * it should write to the location. 862 * 863 * When using call ops, this is called when the associated ops change, even 864 * when (addr == old_addr). 865 * 866 * The code segment at @rec->ip should be a caller to @old_addr 867 * 868 * Return must be: 869 * 0 on success 870 * -EFAULT on error reading the location 871 * -EINVAL on a failed compare of the contents 872 * -EPERM on error writing to the location 873 * Any other value will be considered a failure. 874 */ 875 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 876 unsigned long addr); 877 #else 878 /* Should never be called */ 879 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 880 unsigned long addr) 881 { 882 return -EINVAL; 883 } 884 #endif 885 886 extern int skip_trace(unsigned long ip); 887 extern void ftrace_module_init(struct module *mod); 888 extern void ftrace_module_enable(struct module *mod); 889 extern void ftrace_release_mod(struct module *mod); 890 #else /* CONFIG_DYNAMIC_FTRACE */ 891 static inline int skip_trace(unsigned long ip) { return 0; } 892 static inline void ftrace_module_init(struct module *mod) { } 893 static inline void ftrace_module_enable(struct module *mod) { } 894 static inline void ftrace_release_mod(struct module *mod) { } 895 static inline int ftrace_text_reserved(const void *start, const void *end) 896 { 897 return 0; 898 } 899 static inline unsigned long ftrace_location(unsigned long ip) 900 { 901 return 0; 902 } 903 904 /* 905 * Again users of functions that have ftrace_ops may not 906 * have them defined when ftrace is not enabled, but these 907 * functions may still be called. Use a macro instead of inline. 908 */ 909 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 910 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 911 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 912 #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; }) 913 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 914 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 915 #define ftrace_free_filter(ops) do { } while (0) 916 #define ftrace_ops_set_global_filter(ops) do { } while (0) 917 918 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 919 size_t cnt, loff_t *ppos) { return -ENODEV; } 920 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 921 size_t cnt, loff_t *ppos) { return -ENODEV; } 922 static inline int 923 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 924 925 static inline bool is_ftrace_trampoline(unsigned long addr) 926 { 927 return false; 928 } 929 #endif /* CONFIG_DYNAMIC_FTRACE */ 930 931 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 932 #ifndef ftrace_graph_func 933 #define ftrace_graph_func ftrace_stub 934 #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB 935 #else 936 #define FTRACE_OPS_GRAPH_STUB 0 937 #endif 938 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 939 940 /* totally disable ftrace - can not re-enable after this */ 941 void ftrace_kill(void); 942 943 static inline void tracer_disable(void) 944 { 945 #ifdef CONFIG_FUNCTION_TRACER 946 ftrace_enabled = 0; 947 #endif 948 } 949 950 /* 951 * Ftrace disable/restore without lock. Some synchronization mechanism 952 * must be used to prevent ftrace_enabled to be changed between 953 * disable/restore. 954 */ 955 static inline int __ftrace_enabled_save(void) 956 { 957 #ifdef CONFIG_FUNCTION_TRACER 958 int saved_ftrace_enabled = ftrace_enabled; 959 ftrace_enabled = 0; 960 return saved_ftrace_enabled; 961 #else 962 return 0; 963 #endif 964 } 965 966 static inline void __ftrace_enabled_restore(int enabled) 967 { 968 #ifdef CONFIG_FUNCTION_TRACER 969 ftrace_enabled = enabled; 970 #endif 971 } 972 973 /* All archs should have this, but we define it for consistency */ 974 #ifndef ftrace_return_address0 975 # define ftrace_return_address0 __builtin_return_address(0) 976 #endif 977 978 /* Archs may use other ways for ADDR1 and beyond */ 979 #ifndef ftrace_return_address 980 # ifdef CONFIG_FRAME_POINTER 981 # define ftrace_return_address(n) __builtin_return_address(n) 982 # else 983 # define ftrace_return_address(n) 0UL 984 # endif 985 #endif 986 987 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 988 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 989 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 990 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 991 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 992 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 993 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 994 995 static __always_inline unsigned long get_lock_parent_ip(void) 996 { 997 unsigned long addr = CALLER_ADDR0; 998 999 if (!in_lock_functions(addr)) 1000 return addr; 1001 addr = CALLER_ADDR1; 1002 if (!in_lock_functions(addr)) 1003 return addr; 1004 return CALLER_ADDR2; 1005 } 1006 1007 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE 1008 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 1009 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 1010 #else 1011 /* 1012 * Use defines instead of static inlines because some arches will make code out 1013 * of the CALLER_ADDR, when we really want these to be a real nop. 1014 */ 1015 # define trace_preempt_on(a0, a1) do { } while (0) 1016 # define trace_preempt_off(a0, a1) do { } while (0) 1017 #endif 1018 1019 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 1020 extern void ftrace_init(void); 1021 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY 1022 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries" 1023 #else 1024 #define FTRACE_CALLSITE_SECTION "__mcount_loc" 1025 #endif 1026 #else 1027 static inline void ftrace_init(void) { } 1028 #endif 1029 1030 /* 1031 * Structure that defines an entry function trace. 1032 * It's already packed but the attribute "packed" is needed 1033 * to remove extra padding at the end. 1034 */ 1035 struct ftrace_graph_ent { 1036 unsigned long func; /* Current function */ 1037 int depth; 1038 } __packed; 1039 1040 /* 1041 * Structure that defines an entry function trace with retaddr. 1042 * It's already packed but the attribute "packed" is needed 1043 * to remove extra padding at the end. 1044 */ 1045 struct fgraph_retaddr_ent { 1046 unsigned long func; /* Current function */ 1047 int depth; 1048 unsigned long retaddr; /* Return address */ 1049 } __packed; 1050 1051 /* 1052 * Structure that defines a return function trace. 1053 * It's already packed but the attribute "packed" is needed 1054 * to remove extra padding at the end. 1055 */ 1056 struct ftrace_graph_ret { 1057 unsigned long func; /* Current function */ 1058 #ifdef CONFIG_FUNCTION_GRAPH_RETVAL 1059 unsigned long retval; 1060 #endif 1061 int depth; 1062 /* Number of functions that overran the depth limit for current task */ 1063 unsigned int overrun; 1064 unsigned long long calltime; 1065 unsigned long long rettime; 1066 } __packed; 1067 1068 struct fgraph_ops; 1069 1070 /* Type of the callback handlers for tracing function graph*/ 1071 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *, 1072 struct fgraph_ops *); /* return */ 1073 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *, 1074 struct fgraph_ops *); /* entry */ 1075 1076 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace, 1077 struct fgraph_ops *gops); 1078 bool ftrace_pids_enabled(struct ftrace_ops *ops); 1079 1080 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1081 1082 struct fgraph_ops { 1083 trace_func_graph_ent_t entryfunc; 1084 trace_func_graph_ret_t retfunc; 1085 struct ftrace_ops ops; /* for the hash lists */ 1086 void *private; 1087 trace_func_graph_ent_t saved_func; 1088 int idx; 1089 }; 1090 1091 void *fgraph_reserve_data(int idx, int size_bytes); 1092 void *fgraph_retrieve_data(int idx, int *size_bytes); 1093 void *fgraph_retrieve_parent_data(int idx, int *size_bytes, int depth); 1094 1095 /* 1096 * Stack of return addresses for functions 1097 * of a thread. 1098 * Used in struct thread_info 1099 */ 1100 struct ftrace_ret_stack { 1101 unsigned long ret; 1102 unsigned long func; 1103 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 1104 unsigned long fp; 1105 #endif 1106 unsigned long *retp; 1107 }; 1108 1109 /* 1110 * Primary handler of a function return. 1111 * It relays on ftrace_return_to_handler. 1112 * Defined in entry_32/64.S 1113 */ 1114 extern void return_to_handler(void); 1115 1116 extern int 1117 function_graph_enter(unsigned long ret, unsigned long func, 1118 unsigned long frame_pointer, unsigned long *retp); 1119 1120 struct ftrace_ret_stack * 1121 ftrace_graph_get_ret_stack(struct task_struct *task, int skip); 1122 unsigned long ftrace_graph_top_ret_addr(struct task_struct *task); 1123 1124 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 1125 unsigned long ret, unsigned long *retp); 1126 unsigned long *fgraph_get_task_var(struct fgraph_ops *gops); 1127 1128 /* 1129 * Sometimes we don't want to trace a function with the function 1130 * graph tracer but we want them to keep traced by the usual function 1131 * tracer if the function graph tracer is not configured. 1132 */ 1133 #define __notrace_funcgraph notrace 1134 1135 #define FTRACE_RETFUNC_DEPTH 50 1136 #define FTRACE_RETSTACK_ALLOC_SIZE 32 1137 1138 extern int register_ftrace_graph(struct fgraph_ops *ops); 1139 extern void unregister_ftrace_graph(struct fgraph_ops *ops); 1140 1141 /** 1142 * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called 1143 * 1144 * ftrace_graph_stop() is called when a severe error is detected in 1145 * the function graph tracing. This function is called by the critical 1146 * paths of function graph to keep those paths from doing any more harm. 1147 */ 1148 DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph); 1149 1150 static inline bool ftrace_graph_is_dead(void) 1151 { 1152 return static_branch_unlikely(&kill_ftrace_graph); 1153 } 1154 1155 extern void ftrace_graph_stop(void); 1156 1157 /* The current handlers in use */ 1158 extern trace_func_graph_ret_t ftrace_graph_return; 1159 extern trace_func_graph_ent_t ftrace_graph_entry; 1160 1161 extern void ftrace_graph_init_task(struct task_struct *t); 1162 extern void ftrace_graph_exit_task(struct task_struct *t); 1163 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 1164 1165 /* Used by assembly, but to quiet sparse warnings */ 1166 extern struct ftrace_ops *function_trace_op; 1167 1168 static inline void pause_graph_tracing(void) 1169 { 1170 atomic_inc(¤t->tracing_graph_pause); 1171 } 1172 1173 static inline void unpause_graph_tracing(void) 1174 { 1175 atomic_dec(¤t->tracing_graph_pause); 1176 } 1177 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 1178 1179 #define __notrace_funcgraph 1180 1181 static inline void ftrace_graph_init_task(struct task_struct *t) { } 1182 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 1183 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 1184 1185 /* Define as macros as fgraph_ops may not be defined */ 1186 #define register_ftrace_graph(ops) ({ -1; }) 1187 #define unregister_ftrace_graph(ops) do { } while (0) 1188 1189 static inline unsigned long 1190 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 1191 unsigned long *retp) 1192 { 1193 return ret; 1194 } 1195 1196 static inline void pause_graph_tracing(void) { } 1197 static inline void unpause_graph_tracing(void) { } 1198 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 1199 1200 #ifdef CONFIG_TRACING 1201 enum ftrace_dump_mode; 1202 1203 #define MAX_TRACER_SIZE 100 1204 extern char ftrace_dump_on_oops[]; 1205 extern int ftrace_dump_on_oops_enabled(void); 1206 extern int tracepoint_printk; 1207 1208 extern void disable_trace_on_warning(void); 1209 extern int __disable_trace_on_warning; 1210 1211 int tracepoint_printk_sysctl(const struct ctl_table *table, int write, 1212 void *buffer, size_t *lenp, loff_t *ppos); 1213 1214 #else /* CONFIG_TRACING */ 1215 static inline void disable_trace_on_warning(void) { } 1216 #endif /* CONFIG_TRACING */ 1217 1218 #ifdef CONFIG_FTRACE_SYSCALLS 1219 1220 unsigned long arch_syscall_addr(int nr); 1221 1222 #endif /* CONFIG_FTRACE_SYSCALLS */ 1223 1224 #endif /* _LINUX_FTRACE_H */ 1225