1 /* 2 * Ftrace header. For implementation details beyond the random comments 3 * scattered below, see: Documentation/trace/ftrace-design.txt 4 */ 5 6 #ifndef _LINUX_FTRACE_H 7 #define _LINUX_FTRACE_H 8 9 #include <linux/trace_clock.h> 10 #include <linux/kallsyms.h> 11 #include <linux/linkage.h> 12 #include <linux/bitops.h> 13 #include <linux/module.h> 14 #include <linux/ktime.h> 15 #include <linux/sched.h> 16 #include <linux/types.h> 17 #include <linux/init.h> 18 #include <linux/fs.h> 19 20 #include <asm/ftrace.h> 21 22 struct ftrace_hash; 23 24 #ifdef CONFIG_FUNCTION_TRACER 25 26 extern int ftrace_enabled; 27 extern int 28 ftrace_enable_sysctl(struct ctl_table *table, int write, 29 void __user *buffer, size_t *lenp, 30 loff_t *ppos); 31 32 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip); 33 34 enum { 35 FTRACE_OPS_FL_ENABLED = 1 << 0, 36 FTRACE_OPS_FL_GLOBAL = 1 << 1, 37 FTRACE_OPS_FL_DYNAMIC = 1 << 2, 38 }; 39 40 struct ftrace_ops { 41 ftrace_func_t func; 42 struct ftrace_ops *next; 43 unsigned long flags; 44 #ifdef CONFIG_DYNAMIC_FTRACE 45 struct ftrace_hash *notrace_hash; 46 struct ftrace_hash *filter_hash; 47 #endif 48 }; 49 50 extern int function_trace_stop; 51 52 /* 53 * Type of the current tracing. 54 */ 55 enum ftrace_tracing_type_t { 56 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 57 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 58 }; 59 60 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 61 extern enum ftrace_tracing_type_t ftrace_tracing_type; 62 63 /** 64 * ftrace_stop - stop function tracer. 65 * 66 * A quick way to stop the function tracer. Note this an on off switch, 67 * it is not something that is recursive like preempt_disable. 68 * This does not disable the calling of mcount, it only stops the 69 * calling of functions from mcount. 70 */ 71 static inline void ftrace_stop(void) 72 { 73 function_trace_stop = 1; 74 } 75 76 /** 77 * ftrace_start - start the function tracer. 78 * 79 * This function is the inverse of ftrace_stop. This does not enable 80 * the function tracing if the function tracer is disabled. This only 81 * sets the function tracer flag to continue calling the functions 82 * from mcount. 83 */ 84 static inline void ftrace_start(void) 85 { 86 function_trace_stop = 0; 87 } 88 89 /* 90 * The ftrace_ops must be a static and should also 91 * be read_mostly. These functions do modify read_mostly variables 92 * so use them sparely. Never free an ftrace_op or modify the 93 * next pointer after it has been registered. Even after unregistering 94 * it, the next pointer may still be used internally. 95 */ 96 int register_ftrace_function(struct ftrace_ops *ops); 97 int unregister_ftrace_function(struct ftrace_ops *ops); 98 void clear_ftrace_function(void); 99 100 extern void ftrace_stub(unsigned long a0, unsigned long a1); 101 102 #else /* !CONFIG_FUNCTION_TRACER */ 103 /* 104 * (un)register_ftrace_function must be a macro since the ops parameter 105 * must not be evaluated. 106 */ 107 #define register_ftrace_function(ops) ({ 0; }) 108 #define unregister_ftrace_function(ops) ({ 0; }) 109 static inline void clear_ftrace_function(void) { } 110 static inline void ftrace_kill(void) { } 111 static inline void ftrace_stop(void) { } 112 static inline void ftrace_start(void) { } 113 #endif /* CONFIG_FUNCTION_TRACER */ 114 115 #ifdef CONFIG_STACK_TRACER 116 extern int stack_tracer_enabled; 117 int 118 stack_trace_sysctl(struct ctl_table *table, int write, 119 void __user *buffer, size_t *lenp, 120 loff_t *ppos); 121 #endif 122 123 struct ftrace_func_command { 124 struct list_head list; 125 char *name; 126 int (*func)(struct ftrace_hash *hash, 127 char *func, char *cmd, 128 char *params, int enable); 129 }; 130 131 #ifdef CONFIG_DYNAMIC_FTRACE 132 133 int ftrace_arch_code_modify_prepare(void); 134 int ftrace_arch_code_modify_post_process(void); 135 136 struct seq_file; 137 138 struct ftrace_probe_ops { 139 void (*func)(unsigned long ip, 140 unsigned long parent_ip, 141 void **data); 142 int (*callback)(unsigned long ip, void **data); 143 void (*free)(void **data); 144 int (*print)(struct seq_file *m, 145 unsigned long ip, 146 struct ftrace_probe_ops *ops, 147 void *data); 148 }; 149 150 extern int 151 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 152 void *data); 153 extern void 154 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 155 void *data); 156 extern void 157 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops); 158 extern void unregister_ftrace_function_probe_all(char *glob); 159 160 extern int ftrace_text_reserved(void *start, void *end); 161 162 enum { 163 FTRACE_FL_ENABLED = (1 << 30), 164 FTRACE_FL_FREE = (1 << 31), 165 }; 166 167 #define FTRACE_FL_MASK (0x3UL << 30) 168 #define FTRACE_REF_MAX ((1 << 30) - 1) 169 170 struct dyn_ftrace { 171 union { 172 unsigned long ip; /* address of mcount call-site */ 173 struct dyn_ftrace *freelist; 174 }; 175 union { 176 unsigned long flags; 177 struct dyn_ftrace *newlist; 178 }; 179 struct dyn_arch_ftrace arch; 180 }; 181 182 int ftrace_force_update(void); 183 void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 184 int len, int reset); 185 void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 186 int len, int reset); 187 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 188 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 189 190 int register_ftrace_command(struct ftrace_func_command *cmd); 191 int unregister_ftrace_command(struct ftrace_func_command *cmd); 192 193 /* defined in arch */ 194 extern int ftrace_ip_converted(unsigned long ip); 195 extern int ftrace_dyn_arch_init(void *data); 196 extern int ftrace_update_ftrace_func(ftrace_func_t func); 197 extern void ftrace_caller(void); 198 extern void ftrace_call(void); 199 extern void mcount_call(void); 200 201 #ifndef FTRACE_ADDR 202 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 203 #endif 204 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 205 extern void ftrace_graph_caller(void); 206 extern int ftrace_enable_ftrace_graph_caller(void); 207 extern int ftrace_disable_ftrace_graph_caller(void); 208 #else 209 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 210 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 211 #endif 212 213 /** 214 * ftrace_make_nop - convert code into nop 215 * @mod: module structure if called by module load initialization 216 * @rec: the mcount call site record 217 * @addr: the address that the call site should be calling 218 * 219 * This is a very sensitive operation and great care needs 220 * to be taken by the arch. The operation should carefully 221 * read the location, check to see if what is read is indeed 222 * what we expect it to be, and then on success of the compare, 223 * it should write to the location. 224 * 225 * The code segment at @rec->ip should be a caller to @addr 226 * 227 * Return must be: 228 * 0 on success 229 * -EFAULT on error reading the location 230 * -EINVAL on a failed compare of the contents 231 * -EPERM on error writing to the location 232 * Any other value will be considered a failure. 233 */ 234 extern int ftrace_make_nop(struct module *mod, 235 struct dyn_ftrace *rec, unsigned long addr); 236 237 /** 238 * ftrace_make_call - convert a nop call site into a call to addr 239 * @rec: the mcount call site record 240 * @addr: the address that the call site should call 241 * 242 * This is a very sensitive operation and great care needs 243 * to be taken by the arch. The operation should carefully 244 * read the location, check to see if what is read is indeed 245 * what we expect it to be, and then on success of the compare, 246 * it should write to the location. 247 * 248 * The code segment at @rec->ip should be a nop 249 * 250 * Return must be: 251 * 0 on success 252 * -EFAULT on error reading the location 253 * -EINVAL on a failed compare of the contents 254 * -EPERM on error writing to the location 255 * Any other value will be considered a failure. 256 */ 257 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 258 259 /* May be defined in arch */ 260 extern int ftrace_arch_read_dyn_info(char *buf, int size); 261 262 extern int skip_trace(unsigned long ip); 263 264 extern void ftrace_disable_daemon(void); 265 extern void ftrace_enable_daemon(void); 266 #else 267 static inline int skip_trace(unsigned long ip) { return 0; } 268 static inline int ftrace_force_update(void) { return 0; } 269 static inline void ftrace_set_filter(unsigned char *buf, int len, int reset) 270 { 271 } 272 static inline void ftrace_disable_daemon(void) { } 273 static inline void ftrace_enable_daemon(void) { } 274 static inline void ftrace_release_mod(struct module *mod) {} 275 static inline int register_ftrace_command(struct ftrace_func_command *cmd) 276 { 277 return -EINVAL; 278 } 279 static inline int unregister_ftrace_command(char *cmd_name) 280 { 281 return -EINVAL; 282 } 283 static inline int ftrace_text_reserved(void *start, void *end) 284 { 285 return 0; 286 } 287 #endif /* CONFIG_DYNAMIC_FTRACE */ 288 289 /* totally disable ftrace - can not re-enable after this */ 290 void ftrace_kill(void); 291 292 static inline void tracer_disable(void) 293 { 294 #ifdef CONFIG_FUNCTION_TRACER 295 ftrace_enabled = 0; 296 #endif 297 } 298 299 /* 300 * Ftrace disable/restore without lock. Some synchronization mechanism 301 * must be used to prevent ftrace_enabled to be changed between 302 * disable/restore. 303 */ 304 static inline int __ftrace_enabled_save(void) 305 { 306 #ifdef CONFIG_FUNCTION_TRACER 307 int saved_ftrace_enabled = ftrace_enabled; 308 ftrace_enabled = 0; 309 return saved_ftrace_enabled; 310 #else 311 return 0; 312 #endif 313 } 314 315 static inline void __ftrace_enabled_restore(int enabled) 316 { 317 #ifdef CONFIG_FUNCTION_TRACER 318 ftrace_enabled = enabled; 319 #endif 320 } 321 322 #ifndef HAVE_ARCH_CALLER_ADDR 323 # ifdef CONFIG_FRAME_POINTER 324 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0)) 325 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1)) 326 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2)) 327 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3)) 328 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4)) 329 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5)) 330 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6)) 331 # else 332 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0)) 333 # define CALLER_ADDR1 0UL 334 # define CALLER_ADDR2 0UL 335 # define CALLER_ADDR3 0UL 336 # define CALLER_ADDR4 0UL 337 # define CALLER_ADDR5 0UL 338 # define CALLER_ADDR6 0UL 339 # endif 340 #endif /* ifndef HAVE_ARCH_CALLER_ADDR */ 341 342 #ifdef CONFIG_IRQSOFF_TRACER 343 extern void time_hardirqs_on(unsigned long a0, unsigned long a1); 344 extern void time_hardirqs_off(unsigned long a0, unsigned long a1); 345 #else 346 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } 347 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } 348 #endif 349 350 #ifdef CONFIG_PREEMPT_TRACER 351 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 352 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 353 #else 354 static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { } 355 static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { } 356 #endif 357 358 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 359 extern void ftrace_init(void); 360 #else 361 static inline void ftrace_init(void) { } 362 #endif 363 364 /* 365 * Structure that defines an entry function trace. 366 */ 367 struct ftrace_graph_ent { 368 unsigned long func; /* Current function */ 369 int depth; 370 }; 371 372 /* 373 * Structure that defines a return function trace. 374 */ 375 struct ftrace_graph_ret { 376 unsigned long func; /* Current function */ 377 unsigned long long calltime; 378 unsigned long long rettime; 379 /* Number of functions that overran the depth limit for current task */ 380 unsigned long overrun; 381 int depth; 382 }; 383 384 /* Type of the callback handlers for tracing function graph*/ 385 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 386 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 387 388 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 389 390 /* for init task */ 391 #define INIT_FTRACE_GRAPH .ret_stack = NULL, 392 393 /* 394 * Stack of return addresses for functions 395 * of a thread. 396 * Used in struct thread_info 397 */ 398 struct ftrace_ret_stack { 399 unsigned long ret; 400 unsigned long func; 401 unsigned long long calltime; 402 unsigned long long subtime; 403 unsigned long fp; 404 }; 405 406 /* 407 * Primary handler of a function return. 408 * It relays on ftrace_return_to_handler. 409 * Defined in entry_32/64.S 410 */ 411 extern void return_to_handler(void); 412 413 extern int 414 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 415 unsigned long frame_pointer); 416 417 /* 418 * Sometimes we don't want to trace a function with the function 419 * graph tracer but we want them to keep traced by the usual function 420 * tracer if the function graph tracer is not configured. 421 */ 422 #define __notrace_funcgraph notrace 423 424 /* 425 * We want to which function is an entrypoint of a hardirq. 426 * That will help us to put a signal on output. 427 */ 428 #define __irq_entry __attribute__((__section__(".irqentry.text"))) 429 430 /* Limits of hardirq entrypoints */ 431 extern char __irqentry_text_start[]; 432 extern char __irqentry_text_end[]; 433 434 #define FTRACE_RETFUNC_DEPTH 50 435 #define FTRACE_RETSTACK_ALLOC_SIZE 32 436 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 437 trace_func_graph_ent_t entryfunc); 438 439 extern void ftrace_graph_stop(void); 440 441 /* The current handlers in use */ 442 extern trace_func_graph_ret_t ftrace_graph_return; 443 extern trace_func_graph_ent_t ftrace_graph_entry; 444 445 extern void unregister_ftrace_graph(void); 446 447 extern void ftrace_graph_init_task(struct task_struct *t); 448 extern void ftrace_graph_exit_task(struct task_struct *t); 449 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 450 451 static inline int task_curr_ret_stack(struct task_struct *t) 452 { 453 return t->curr_ret_stack; 454 } 455 456 static inline void pause_graph_tracing(void) 457 { 458 atomic_inc(¤t->tracing_graph_pause); 459 } 460 461 static inline void unpause_graph_tracing(void) 462 { 463 atomic_dec(¤t->tracing_graph_pause); 464 } 465 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 466 467 #define __notrace_funcgraph 468 #define __irq_entry 469 #define INIT_FTRACE_GRAPH 470 471 static inline void ftrace_graph_init_task(struct task_struct *t) { } 472 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 473 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 474 475 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 476 trace_func_graph_ent_t entryfunc) 477 { 478 return -1; 479 } 480 static inline void unregister_ftrace_graph(void) { } 481 482 static inline int task_curr_ret_stack(struct task_struct *tsk) 483 { 484 return -1; 485 } 486 487 static inline void pause_graph_tracing(void) { } 488 static inline void unpause_graph_tracing(void) { } 489 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 490 491 #ifdef CONFIG_TRACING 492 493 /* flags for current->trace */ 494 enum { 495 TSK_TRACE_FL_TRACE_BIT = 0, 496 TSK_TRACE_FL_GRAPH_BIT = 1, 497 }; 498 enum { 499 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 500 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 501 }; 502 503 static inline void set_tsk_trace_trace(struct task_struct *tsk) 504 { 505 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 506 } 507 508 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 509 { 510 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 511 } 512 513 static inline int test_tsk_trace_trace(struct task_struct *tsk) 514 { 515 return tsk->trace & TSK_TRACE_FL_TRACE; 516 } 517 518 static inline void set_tsk_trace_graph(struct task_struct *tsk) 519 { 520 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 521 } 522 523 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 524 { 525 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 526 } 527 528 static inline int test_tsk_trace_graph(struct task_struct *tsk) 529 { 530 return tsk->trace & TSK_TRACE_FL_GRAPH; 531 } 532 533 enum ftrace_dump_mode; 534 535 extern enum ftrace_dump_mode ftrace_dump_on_oops; 536 537 #ifdef CONFIG_PREEMPT 538 #define INIT_TRACE_RECURSION .trace_recursion = 0, 539 #endif 540 541 #endif /* CONFIG_TRACING */ 542 543 #ifndef INIT_TRACE_RECURSION 544 #define INIT_TRACE_RECURSION 545 #endif 546 547 #ifdef CONFIG_FTRACE_SYSCALLS 548 549 unsigned long arch_syscall_addr(int nr); 550 551 #endif /* CONFIG_FTRACE_SYSCALLS */ 552 553 #endif /* _LINUX_FTRACE_H */ 554