1 #ifndef _LINUX_KERNEL_TRACE_H 2 #define _LINUX_KERNEL_TRACE_H 3 4 #include <linux/fs.h> 5 #include <asm/atomic.h> 6 #include <linux/sched.h> 7 #include <linux/clocksource.h> 8 #include <linux/ring_buffer.h> 9 #include <linux/mmiotrace.h> 10 #include <linux/tracepoint.h> 11 #include <linux/ftrace.h> 12 #include <trace/boot.h> 13 #include <linux/kmemtrace.h> 14 #include <linux/hw_breakpoint.h> 15 16 #include <linux/trace_seq.h> 17 #include <linux/ftrace_event.h> 18 19 enum trace_type { 20 __TRACE_FIRST_TYPE = 0, 21 22 TRACE_FN, 23 TRACE_CTX, 24 TRACE_WAKE, 25 TRACE_STACK, 26 TRACE_PRINT, 27 TRACE_BPRINT, 28 TRACE_SPECIAL, 29 TRACE_MMIO_RW, 30 TRACE_MMIO_MAP, 31 TRACE_BRANCH, 32 TRACE_BOOT_CALL, 33 TRACE_BOOT_RET, 34 TRACE_GRAPH_RET, 35 TRACE_GRAPH_ENT, 36 TRACE_USER_STACK, 37 TRACE_HW_BRANCHES, 38 TRACE_KMEM_ALLOC, 39 TRACE_KMEM_FREE, 40 TRACE_BLK, 41 TRACE_KSYM, 42 43 __TRACE_LAST_TYPE, 44 }; 45 46 enum kmemtrace_type_id { 47 KMEMTRACE_TYPE_KMALLOC = 0, /* kmalloc() or kfree(). */ 48 KMEMTRACE_TYPE_CACHE, /* kmem_cache_*(). */ 49 KMEMTRACE_TYPE_PAGES, /* __get_free_pages() and friends. */ 50 }; 51 52 extern struct tracer boot_tracer; 53 54 #undef __field 55 #define __field(type, item) type item; 56 57 #undef __field_struct 58 #define __field_struct(type, item) __field(type, item) 59 60 #undef __field_desc 61 #define __field_desc(type, container, item) 62 63 #undef __array 64 #define __array(type, item, size) type item[size]; 65 66 #undef __array_desc 67 #define __array_desc(type, container, item, size) 68 69 #undef __dynamic_array 70 #define __dynamic_array(type, item) type item[]; 71 72 #undef F_STRUCT 73 #define F_STRUCT(args...) args 74 75 #undef FTRACE_ENTRY 76 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print) \ 77 struct struct_name { \ 78 struct trace_entry ent; \ 79 tstruct \ 80 } 81 82 #undef TP_ARGS 83 #define TP_ARGS(args...) args 84 85 #undef FTRACE_ENTRY_DUP 86 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk) 87 88 #include "trace_entries.h" 89 90 /* 91 * syscalls are special, and need special handling, this is why 92 * they are not included in trace_entries.h 93 */ 94 struct syscall_trace_enter { 95 struct trace_entry ent; 96 int nr; 97 unsigned long args[]; 98 }; 99 100 struct syscall_trace_exit { 101 struct trace_entry ent; 102 int nr; 103 long ret; 104 }; 105 106 struct kprobe_trace_entry { 107 struct trace_entry ent; 108 unsigned long ip; 109 int nargs; 110 unsigned long args[]; 111 }; 112 113 #define SIZEOF_KPROBE_TRACE_ENTRY(n) \ 114 (offsetof(struct kprobe_trace_entry, args) + \ 115 (sizeof(unsigned long) * (n))) 116 117 struct kretprobe_trace_entry { 118 struct trace_entry ent; 119 unsigned long func; 120 unsigned long ret_ip; 121 int nargs; 122 unsigned long args[]; 123 }; 124 125 #define SIZEOF_KRETPROBE_TRACE_ENTRY(n) \ 126 (offsetof(struct kretprobe_trace_entry, args) + \ 127 (sizeof(unsigned long) * (n))) 128 129 /* 130 * trace_flag_type is an enumeration that holds different 131 * states when a trace occurs. These are: 132 * IRQS_OFF - interrupts were disabled 133 * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags 134 * NEED_RESCHED - reschedule is requested 135 * HARDIRQ - inside an interrupt handler 136 * SOFTIRQ - inside a softirq handler 137 */ 138 enum trace_flag_type { 139 TRACE_FLAG_IRQS_OFF = 0x01, 140 TRACE_FLAG_IRQS_NOSUPPORT = 0x02, 141 TRACE_FLAG_NEED_RESCHED = 0x04, 142 TRACE_FLAG_HARDIRQ = 0x08, 143 TRACE_FLAG_SOFTIRQ = 0x10, 144 }; 145 146 #define TRACE_BUF_SIZE 1024 147 148 /* 149 * The CPU trace array - it consists of thousands of trace entries 150 * plus some other descriptor data: (for example which task started 151 * the trace, etc.) 152 */ 153 struct trace_array_cpu { 154 atomic_t disabled; 155 void *buffer_page; /* ring buffer spare */ 156 157 unsigned long saved_latency; 158 unsigned long critical_start; 159 unsigned long critical_end; 160 unsigned long critical_sequence; 161 unsigned long nice; 162 unsigned long policy; 163 unsigned long rt_priority; 164 unsigned long skipped_entries; 165 cycle_t preempt_timestamp; 166 pid_t pid; 167 uid_t uid; 168 char comm[TASK_COMM_LEN]; 169 }; 170 171 /* 172 * The trace array - an array of per-CPU trace arrays. This is the 173 * highest level data structure that individual tracers deal with. 174 * They have on/off state as well: 175 */ 176 struct trace_array { 177 struct ring_buffer *buffer; 178 unsigned long entries; 179 int cpu; 180 cycle_t time_start; 181 struct task_struct *waiter; 182 struct trace_array_cpu *data[NR_CPUS]; 183 }; 184 185 #define FTRACE_CMP_TYPE(var, type) \ 186 __builtin_types_compatible_p(typeof(var), type *) 187 188 #undef IF_ASSIGN 189 #define IF_ASSIGN(var, entry, etype, id) \ 190 if (FTRACE_CMP_TYPE(var, etype)) { \ 191 var = (typeof(var))(entry); \ 192 WARN_ON(id && (entry)->type != id); \ 193 break; \ 194 } 195 196 /* Will cause compile errors if type is not found. */ 197 extern void __ftrace_bad_type(void); 198 199 /* 200 * The trace_assign_type is a verifier that the entry type is 201 * the same as the type being assigned. To add new types simply 202 * add a line with the following format: 203 * 204 * IF_ASSIGN(var, ent, type, id); 205 * 206 * Where "type" is the trace type that includes the trace_entry 207 * as the "ent" item. And "id" is the trace identifier that is 208 * used in the trace_type enum. 209 * 210 * If the type can have more than one id, then use zero. 211 */ 212 #define trace_assign_type(var, ent) \ 213 do { \ 214 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \ 215 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \ 216 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \ 217 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\ 218 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \ 219 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \ 220 IF_ASSIGN(var, ent, struct special_entry, 0); \ 221 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ 222 TRACE_MMIO_RW); \ 223 IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ 224 TRACE_MMIO_MAP); \ 225 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\ 226 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\ 227 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \ 228 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \ 229 TRACE_GRAPH_ENT); \ 230 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ 231 TRACE_GRAPH_RET); \ 232 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\ 233 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry, \ 234 TRACE_KMEM_ALLOC); \ 235 IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \ 236 TRACE_KMEM_FREE); \ 237 IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\ 238 __ftrace_bad_type(); \ 239 } while (0) 240 241 /* 242 * An option specific to a tracer. This is a boolean value. 243 * The bit is the bit index that sets its value on the 244 * flags value in struct tracer_flags. 245 */ 246 struct tracer_opt { 247 const char *name; /* Will appear on the trace_options file */ 248 u32 bit; /* Mask assigned in val field in tracer_flags */ 249 }; 250 251 /* 252 * The set of specific options for a tracer. Your tracer 253 * have to set the initial value of the flags val. 254 */ 255 struct tracer_flags { 256 u32 val; 257 struct tracer_opt *opts; 258 }; 259 260 /* Makes more easy to define a tracer opt */ 261 #define TRACER_OPT(s, b) .name = #s, .bit = b 262 263 264 /** 265 * struct tracer - a specific tracer and its callbacks to interact with debugfs 266 * @name: the name chosen to select it on the available_tracers file 267 * @init: called when one switches to this tracer (echo name > current_tracer) 268 * @reset: called when one switches to another tracer 269 * @start: called when tracing is unpaused (echo 1 > tracing_enabled) 270 * @stop: called when tracing is paused (echo 0 > tracing_enabled) 271 * @open: called when the trace file is opened 272 * @pipe_open: called when the trace_pipe file is opened 273 * @wait_pipe: override how the user waits for traces on trace_pipe 274 * @close: called when the trace file is released 275 * @pipe_close: called when the trace_pipe file is released 276 * @read: override the default read callback on trace_pipe 277 * @splice_read: override the default splice_read callback on trace_pipe 278 * @selftest: selftest to run on boot (see trace_selftest.c) 279 * @print_headers: override the first lines that describe your columns 280 * @print_line: callback that prints a trace 281 * @set_flag: signals one of your private flags changed (trace_options file) 282 * @flags: your private flags 283 */ 284 struct tracer { 285 const char *name; 286 int (*init)(struct trace_array *tr); 287 void (*reset)(struct trace_array *tr); 288 void (*start)(struct trace_array *tr); 289 void (*stop)(struct trace_array *tr); 290 void (*open)(struct trace_iterator *iter); 291 void (*pipe_open)(struct trace_iterator *iter); 292 void (*wait_pipe)(struct trace_iterator *iter); 293 void (*close)(struct trace_iterator *iter); 294 void (*pipe_close)(struct trace_iterator *iter); 295 ssize_t (*read)(struct trace_iterator *iter, 296 struct file *filp, char __user *ubuf, 297 size_t cnt, loff_t *ppos); 298 ssize_t (*splice_read)(struct trace_iterator *iter, 299 struct file *filp, 300 loff_t *ppos, 301 struct pipe_inode_info *pipe, 302 size_t len, 303 unsigned int flags); 304 #ifdef CONFIG_FTRACE_STARTUP_TEST 305 int (*selftest)(struct tracer *trace, 306 struct trace_array *tr); 307 #endif 308 void (*print_header)(struct seq_file *m); 309 enum print_line_t (*print_line)(struct trace_iterator *iter); 310 /* If you handled the flag setting, return 0 */ 311 int (*set_flag)(u32 old_flags, u32 bit, int set); 312 struct tracer *next; 313 int print_max; 314 struct tracer_flags *flags; 315 }; 316 317 318 #define TRACE_PIPE_ALL_CPU -1 319 320 int tracer_init(struct tracer *t, struct trace_array *tr); 321 int tracing_is_enabled(void); 322 void trace_wake_up(void); 323 void tracing_reset(struct trace_array *tr, int cpu); 324 void tracing_reset_online_cpus(struct trace_array *tr); 325 void tracing_reset_current(int cpu); 326 void tracing_reset_current_online_cpus(void); 327 int tracing_open_generic(struct inode *inode, struct file *filp); 328 struct dentry *trace_create_file(const char *name, 329 mode_t mode, 330 struct dentry *parent, 331 void *data, 332 const struct file_operations *fops); 333 334 struct dentry *tracing_init_dentry(void); 335 void init_tracer_sysprof_debugfs(struct dentry *d_tracer); 336 337 struct ring_buffer_event; 338 339 struct ring_buffer_event * 340 trace_buffer_lock_reserve(struct ring_buffer *buffer, 341 int type, 342 unsigned long len, 343 unsigned long flags, 344 int pc); 345 void trace_buffer_unlock_commit(struct ring_buffer *buffer, 346 struct ring_buffer_event *event, 347 unsigned long flags, int pc); 348 349 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, 350 struct trace_array_cpu *data); 351 352 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, 353 int *ent_cpu, u64 *ent_ts); 354 355 void default_wait_pipe(struct trace_iterator *iter); 356 void poll_wait_pipe(struct trace_iterator *iter); 357 358 void ftrace(struct trace_array *tr, 359 struct trace_array_cpu *data, 360 unsigned long ip, 361 unsigned long parent_ip, 362 unsigned long flags, int pc); 363 void tracing_sched_switch_trace(struct trace_array *tr, 364 struct task_struct *prev, 365 struct task_struct *next, 366 unsigned long flags, int pc); 367 368 void tracing_sched_wakeup_trace(struct trace_array *tr, 369 struct task_struct *wakee, 370 struct task_struct *cur, 371 unsigned long flags, int pc); 372 void trace_special(struct trace_array *tr, 373 struct trace_array_cpu *data, 374 unsigned long arg1, 375 unsigned long arg2, 376 unsigned long arg3, int pc); 377 void trace_function(struct trace_array *tr, 378 unsigned long ip, 379 unsigned long parent_ip, 380 unsigned long flags, int pc); 381 382 void trace_graph_return(struct ftrace_graph_ret *trace); 383 int trace_graph_entry(struct ftrace_graph_ent *trace); 384 void set_graph_array(struct trace_array *tr); 385 386 void tracing_start_cmdline_record(void); 387 void tracing_stop_cmdline_record(void); 388 void tracing_sched_switch_assign_trace(struct trace_array *tr); 389 void tracing_stop_sched_switch_record(void); 390 void tracing_start_sched_switch_record(void); 391 int register_tracer(struct tracer *type); 392 void unregister_tracer(struct tracer *type); 393 int is_tracing_stopped(void); 394 395 extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr); 396 397 extern unsigned long nsecs_to_usecs(unsigned long nsecs); 398 399 extern unsigned long tracing_thresh; 400 401 #ifdef CONFIG_TRACER_MAX_TRACE 402 extern unsigned long tracing_max_latency; 403 404 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu); 405 void update_max_tr_single(struct trace_array *tr, 406 struct task_struct *tsk, int cpu); 407 #endif /* CONFIG_TRACER_MAX_TRACE */ 408 409 #ifdef CONFIG_STACKTRACE 410 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags, 411 int skip, int pc); 412 413 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, 414 int pc); 415 416 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, 417 int pc); 418 #else 419 static inline void ftrace_trace_stack(struct trace_array *tr, 420 unsigned long flags, int skip, int pc) 421 { 422 } 423 424 static inline void ftrace_trace_userstack(struct trace_array *tr, 425 unsigned long flags, int pc) 426 { 427 } 428 429 static inline void __trace_stack(struct trace_array *tr, unsigned long flags, 430 int skip, int pc) 431 { 432 } 433 #endif /* CONFIG_STACKTRACE */ 434 435 extern cycle_t ftrace_now(int cpu); 436 437 extern void trace_find_cmdline(int pid, char comm[]); 438 439 #ifdef CONFIG_DYNAMIC_FTRACE 440 extern unsigned long ftrace_update_tot_cnt; 441 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func 442 extern int DYN_FTRACE_TEST_NAME(void); 443 #endif 444 445 extern int ring_buffer_expanded; 446 extern bool tracing_selftest_disabled; 447 DECLARE_PER_CPU(int, ftrace_cpu_disabled); 448 449 #ifdef CONFIG_FTRACE_STARTUP_TEST 450 extern int trace_selftest_startup_function(struct tracer *trace, 451 struct trace_array *tr); 452 extern int trace_selftest_startup_function_graph(struct tracer *trace, 453 struct trace_array *tr); 454 extern int trace_selftest_startup_irqsoff(struct tracer *trace, 455 struct trace_array *tr); 456 extern int trace_selftest_startup_preemptoff(struct tracer *trace, 457 struct trace_array *tr); 458 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace, 459 struct trace_array *tr); 460 extern int trace_selftest_startup_wakeup(struct tracer *trace, 461 struct trace_array *tr); 462 extern int trace_selftest_startup_nop(struct tracer *trace, 463 struct trace_array *tr); 464 extern int trace_selftest_startup_sched_switch(struct tracer *trace, 465 struct trace_array *tr); 466 extern int trace_selftest_startup_sysprof(struct tracer *trace, 467 struct trace_array *tr); 468 extern int trace_selftest_startup_branch(struct tracer *trace, 469 struct trace_array *tr); 470 extern int trace_selftest_startup_hw_branches(struct tracer *trace, 471 struct trace_array *tr); 472 extern int trace_selftest_startup_ksym(struct tracer *trace, 473 struct trace_array *tr); 474 #endif /* CONFIG_FTRACE_STARTUP_TEST */ 475 476 extern void *head_page(struct trace_array_cpu *data); 477 extern unsigned long long ns2usecs(cycle_t nsec); 478 extern int 479 trace_vbprintk(unsigned long ip, const char *fmt, va_list args); 480 extern int 481 trace_vprintk(unsigned long ip, const char *fmt, va_list args); 482 extern int 483 trace_array_vprintk(struct trace_array *tr, 484 unsigned long ip, const char *fmt, va_list args); 485 int trace_array_printk(struct trace_array *tr, 486 unsigned long ip, const char *fmt, ...); 487 488 extern unsigned long trace_flags; 489 490 extern int trace_clock_id; 491 492 /* Standard output formatting function used for function return traces */ 493 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 494 extern enum print_line_t print_graph_function(struct trace_iterator *iter); 495 extern enum print_line_t 496 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s); 497 498 #ifdef CONFIG_DYNAMIC_FTRACE 499 /* TODO: make this variable */ 500 #define FTRACE_GRAPH_MAX_FUNCS 32 501 extern int ftrace_graph_filter_enabled; 502 extern int ftrace_graph_count; 503 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS]; 504 505 static inline int ftrace_graph_addr(unsigned long addr) 506 { 507 int i; 508 509 if (!ftrace_graph_filter_enabled) 510 return 1; 511 512 for (i = 0; i < ftrace_graph_count; i++) { 513 if (addr == ftrace_graph_funcs[i]) 514 return 1; 515 } 516 517 return 0; 518 } 519 #else 520 static inline int ftrace_graph_addr(unsigned long addr) 521 { 522 return 1; 523 } 524 #endif /* CONFIG_DYNAMIC_FTRACE */ 525 #else /* CONFIG_FUNCTION_GRAPH_TRACER */ 526 static inline enum print_line_t 527 print_graph_function(struct trace_iterator *iter) 528 { 529 return TRACE_TYPE_UNHANDLED; 530 } 531 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 532 533 extern struct list_head ftrace_pids; 534 535 #ifdef CONFIG_FUNCTION_TRACER 536 static inline int ftrace_trace_task(struct task_struct *task) 537 { 538 if (list_empty(&ftrace_pids)) 539 return 1; 540 541 return test_tsk_trace_trace(task); 542 } 543 #else 544 static inline int ftrace_trace_task(struct task_struct *task) 545 { 546 return 1; 547 } 548 #endif 549 550 /* 551 * struct trace_parser - servers for reading the user input separated by spaces 552 * @cont: set if the input is not complete - no final space char was found 553 * @buffer: holds the parsed user input 554 * @idx: user input length 555 * @size: buffer size 556 */ 557 struct trace_parser { 558 bool cont; 559 char *buffer; 560 unsigned idx; 561 unsigned size; 562 }; 563 564 static inline bool trace_parser_loaded(struct trace_parser *parser) 565 { 566 return (parser->idx != 0); 567 } 568 569 static inline bool trace_parser_cont(struct trace_parser *parser) 570 { 571 return parser->cont; 572 } 573 574 static inline void trace_parser_clear(struct trace_parser *parser) 575 { 576 parser->cont = false; 577 parser->idx = 0; 578 } 579 580 extern int trace_parser_get_init(struct trace_parser *parser, int size); 581 extern void trace_parser_put(struct trace_parser *parser); 582 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf, 583 size_t cnt, loff_t *ppos); 584 585 /* 586 * trace_iterator_flags is an enumeration that defines bit 587 * positions into trace_flags that controls the output. 588 * 589 * NOTE: These bits must match the trace_options array in 590 * trace.c. 591 */ 592 enum trace_iterator_flags { 593 TRACE_ITER_PRINT_PARENT = 0x01, 594 TRACE_ITER_SYM_OFFSET = 0x02, 595 TRACE_ITER_SYM_ADDR = 0x04, 596 TRACE_ITER_VERBOSE = 0x08, 597 TRACE_ITER_RAW = 0x10, 598 TRACE_ITER_HEX = 0x20, 599 TRACE_ITER_BIN = 0x40, 600 TRACE_ITER_BLOCK = 0x80, 601 TRACE_ITER_STACKTRACE = 0x100, 602 TRACE_ITER_PRINTK = 0x200, 603 TRACE_ITER_PREEMPTONLY = 0x400, 604 TRACE_ITER_BRANCH = 0x800, 605 TRACE_ITER_ANNOTATE = 0x1000, 606 TRACE_ITER_USERSTACKTRACE = 0x2000, 607 TRACE_ITER_SYM_USEROBJ = 0x4000, 608 TRACE_ITER_PRINTK_MSGONLY = 0x8000, 609 TRACE_ITER_CONTEXT_INFO = 0x10000, /* Print pid/cpu/time */ 610 TRACE_ITER_LATENCY_FMT = 0x20000, 611 TRACE_ITER_SLEEP_TIME = 0x40000, 612 TRACE_ITER_GRAPH_TIME = 0x80000, 613 }; 614 615 /* 616 * TRACE_ITER_SYM_MASK masks the options in trace_flags that 617 * control the output of kernel symbols. 618 */ 619 #define TRACE_ITER_SYM_MASK \ 620 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) 621 622 extern struct tracer nop_trace; 623 624 /** 625 * ftrace_preempt_disable - disable preemption scheduler safe 626 * 627 * When tracing can happen inside the scheduler, there exists 628 * cases that the tracing might happen before the need_resched 629 * flag is checked. If this happens and the tracer calls 630 * preempt_enable (after a disable), a schedule might take place 631 * causing an infinite recursion. 632 * 633 * To prevent this, we read the need_resched flag before 634 * disabling preemption. When we want to enable preemption we 635 * check the flag, if it is set, then we call preempt_enable_no_resched. 636 * Otherwise, we call preempt_enable. 637 * 638 * The rational for doing the above is that if need_resched is set 639 * and we have yet to reschedule, we are either in an atomic location 640 * (where we do not need to check for scheduling) or we are inside 641 * the scheduler and do not want to resched. 642 */ 643 static inline int ftrace_preempt_disable(void) 644 { 645 int resched; 646 647 resched = need_resched(); 648 preempt_disable_notrace(); 649 650 return resched; 651 } 652 653 /** 654 * ftrace_preempt_enable - enable preemption scheduler safe 655 * @resched: the return value from ftrace_preempt_disable 656 * 657 * This is a scheduler safe way to enable preemption and not miss 658 * any preemption checks. The disabled saved the state of preemption. 659 * If resched is set, then we are either inside an atomic or 660 * are inside the scheduler (we would have already scheduled 661 * otherwise). In this case, we do not want to call normal 662 * preempt_enable, but preempt_enable_no_resched instead. 663 */ 664 static inline void ftrace_preempt_enable(int resched) 665 { 666 if (resched) 667 preempt_enable_no_resched_notrace(); 668 else 669 preempt_enable_notrace(); 670 } 671 672 #ifdef CONFIG_BRANCH_TRACER 673 extern int enable_branch_tracing(struct trace_array *tr); 674 extern void disable_branch_tracing(void); 675 static inline int trace_branch_enable(struct trace_array *tr) 676 { 677 if (trace_flags & TRACE_ITER_BRANCH) 678 return enable_branch_tracing(tr); 679 return 0; 680 } 681 static inline void trace_branch_disable(void) 682 { 683 /* due to races, always disable */ 684 disable_branch_tracing(); 685 } 686 #else 687 static inline int trace_branch_enable(struct trace_array *tr) 688 { 689 return 0; 690 } 691 static inline void trace_branch_disable(void) 692 { 693 } 694 #endif /* CONFIG_BRANCH_TRACER */ 695 696 /* set ring buffers to default size if not already done so */ 697 int tracing_update_buffers(void); 698 699 /* trace event type bit fields, not numeric */ 700 enum { 701 TRACE_EVENT_TYPE_PRINTF = 1, 702 TRACE_EVENT_TYPE_RAW = 2, 703 }; 704 705 struct ftrace_event_field { 706 struct list_head link; 707 char *name; 708 char *type; 709 int filter_type; 710 int offset; 711 int size; 712 int is_signed; 713 }; 714 715 struct event_filter { 716 int n_preds; 717 struct filter_pred **preds; 718 char *filter_string; 719 }; 720 721 struct event_subsystem { 722 struct list_head list; 723 const char *name; 724 struct dentry *entry; 725 struct event_filter *filter; 726 int nr_events; 727 }; 728 729 struct filter_pred; 730 struct regex; 731 732 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event, 733 int val1, int val2); 734 735 typedef int (*regex_match_func)(char *str, struct regex *r, int len); 736 737 enum regex_type { 738 MATCH_FULL = 0, 739 MATCH_FRONT_ONLY, 740 MATCH_MIDDLE_ONLY, 741 MATCH_END_ONLY, 742 }; 743 744 struct regex { 745 char pattern[MAX_FILTER_STR_VAL]; 746 int len; 747 int field_len; 748 regex_match_func match; 749 }; 750 751 struct filter_pred { 752 filter_pred_fn_t fn; 753 u64 val; 754 struct regex regex; 755 char *field_name; 756 int offset; 757 int not; 758 int op; 759 int pop_n; 760 }; 761 762 extern enum regex_type 763 filter_parse_regex(char *buff, int len, char **search, int *not); 764 extern void print_event_filter(struct ftrace_event_call *call, 765 struct trace_seq *s); 766 extern int apply_event_filter(struct ftrace_event_call *call, 767 char *filter_string); 768 extern int apply_subsystem_event_filter(struct event_subsystem *system, 769 char *filter_string); 770 extern void print_subsystem_event_filter(struct event_subsystem *system, 771 struct trace_seq *s); 772 extern int filter_assign_type(const char *type); 773 774 static inline int 775 filter_check_discard(struct ftrace_event_call *call, void *rec, 776 struct ring_buffer *buffer, 777 struct ring_buffer_event *event) 778 { 779 if (unlikely(call->filter_active) && 780 !filter_match_preds(call->filter, rec)) { 781 ring_buffer_discard_commit(buffer, event); 782 return 1; 783 } 784 785 return 0; 786 } 787 788 extern struct mutex event_mutex; 789 extern struct list_head ftrace_events; 790 791 extern const char *__start___trace_bprintk_fmt[]; 792 extern const char *__stop___trace_bprintk_fmt[]; 793 794 #undef FTRACE_ENTRY 795 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print) \ 796 extern struct ftrace_event_call \ 797 __attribute__((__aligned__(4))) event_##call; 798 #undef FTRACE_ENTRY_DUP 799 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print) \ 800 FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print)) 801 #include "trace_entries.h" 802 803 #endif /* _LINUX_KERNEL_TRACE_H */ 804