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/ftrace.h> 11 #include <trace/boot.h> 12 #include <linux/kmemtrace.h> 13 #include <trace/power.h> 14 15 #include <linux/trace_seq.h> 16 #include <linux/ftrace_event.h> 17 18 enum trace_type { 19 __TRACE_FIRST_TYPE = 0, 20 21 TRACE_FN, 22 TRACE_CTX, 23 TRACE_WAKE, 24 TRACE_STACK, 25 TRACE_PRINT, 26 TRACE_BPRINT, 27 TRACE_SPECIAL, 28 TRACE_MMIO_RW, 29 TRACE_MMIO_MAP, 30 TRACE_BRANCH, 31 TRACE_BOOT_CALL, 32 TRACE_BOOT_RET, 33 TRACE_GRAPH_RET, 34 TRACE_GRAPH_ENT, 35 TRACE_USER_STACK, 36 TRACE_HW_BRANCHES, 37 TRACE_KMEM_ALLOC, 38 TRACE_KMEM_FREE, 39 TRACE_POWER, 40 TRACE_BLK, 41 42 __TRACE_LAST_TYPE, 43 }; 44 45 /* 46 * Function trace entry - function address and parent function addres: 47 */ 48 struct ftrace_entry { 49 struct trace_entry ent; 50 unsigned long ip; 51 unsigned long parent_ip; 52 }; 53 54 /* Function call entry */ 55 struct ftrace_graph_ent_entry { 56 struct trace_entry ent; 57 struct ftrace_graph_ent graph_ent; 58 }; 59 60 /* Function return entry */ 61 struct ftrace_graph_ret_entry { 62 struct trace_entry ent; 63 struct ftrace_graph_ret ret; 64 }; 65 extern struct tracer boot_tracer; 66 67 /* 68 * Context switch trace entry - which task (and prio) we switched from/to: 69 */ 70 struct ctx_switch_entry { 71 struct trace_entry ent; 72 unsigned int prev_pid; 73 unsigned char prev_prio; 74 unsigned char prev_state; 75 unsigned int next_pid; 76 unsigned char next_prio; 77 unsigned char next_state; 78 unsigned int next_cpu; 79 }; 80 81 /* 82 * Special (free-form) trace entry: 83 */ 84 struct special_entry { 85 struct trace_entry ent; 86 unsigned long arg1; 87 unsigned long arg2; 88 unsigned long arg3; 89 }; 90 91 /* 92 * Stack-trace entry: 93 */ 94 95 #define FTRACE_STACK_ENTRIES 8 96 97 struct stack_entry { 98 struct trace_entry ent; 99 unsigned long caller[FTRACE_STACK_ENTRIES]; 100 }; 101 102 struct userstack_entry { 103 struct trace_entry ent; 104 unsigned long caller[FTRACE_STACK_ENTRIES]; 105 }; 106 107 /* 108 * trace_printk entry: 109 */ 110 struct bprint_entry { 111 struct trace_entry ent; 112 unsigned long ip; 113 const char *fmt; 114 u32 buf[]; 115 }; 116 117 struct print_entry { 118 struct trace_entry ent; 119 unsigned long ip; 120 char buf[]; 121 }; 122 123 #define TRACE_OLD_SIZE 88 124 125 struct trace_field_cont { 126 unsigned char type; 127 /* Temporary till we get rid of this completely */ 128 char buf[TRACE_OLD_SIZE - 1]; 129 }; 130 131 struct trace_mmiotrace_rw { 132 struct trace_entry ent; 133 struct mmiotrace_rw rw; 134 }; 135 136 struct trace_mmiotrace_map { 137 struct trace_entry ent; 138 struct mmiotrace_map map; 139 }; 140 141 struct trace_boot_call { 142 struct trace_entry ent; 143 struct boot_trace_call boot_call; 144 }; 145 146 struct trace_boot_ret { 147 struct trace_entry ent; 148 struct boot_trace_ret boot_ret; 149 }; 150 151 #define TRACE_FUNC_SIZE 30 152 #define TRACE_FILE_SIZE 20 153 struct trace_branch { 154 struct trace_entry ent; 155 unsigned line; 156 char func[TRACE_FUNC_SIZE+1]; 157 char file[TRACE_FILE_SIZE+1]; 158 char correct; 159 }; 160 161 struct hw_branch_entry { 162 struct trace_entry ent; 163 u64 from; 164 u64 to; 165 }; 166 167 struct trace_power { 168 struct trace_entry ent; 169 struct power_trace state_data; 170 }; 171 172 enum kmemtrace_type_id { 173 KMEMTRACE_TYPE_KMALLOC = 0, /* kmalloc() or kfree(). */ 174 KMEMTRACE_TYPE_CACHE, /* kmem_cache_*(). */ 175 KMEMTRACE_TYPE_PAGES, /* __get_free_pages() and friends. */ 176 }; 177 178 struct kmemtrace_alloc_entry { 179 struct trace_entry ent; 180 enum kmemtrace_type_id type_id; 181 unsigned long call_site; 182 const void *ptr; 183 size_t bytes_req; 184 size_t bytes_alloc; 185 gfp_t gfp_flags; 186 int node; 187 }; 188 189 struct kmemtrace_free_entry { 190 struct trace_entry ent; 191 enum kmemtrace_type_id type_id; 192 unsigned long call_site; 193 const void *ptr; 194 }; 195 196 struct syscall_trace_enter { 197 struct trace_entry ent; 198 int nr; 199 unsigned long args[]; 200 }; 201 202 struct syscall_trace_exit { 203 struct trace_entry ent; 204 int nr; 205 unsigned long ret; 206 }; 207 208 209 /* 210 * trace_flag_type is an enumeration that holds different 211 * states when a trace occurs. These are: 212 * IRQS_OFF - interrupts were disabled 213 * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags 214 * NEED_RESCED - reschedule is requested 215 * HARDIRQ - inside an interrupt handler 216 * SOFTIRQ - inside a softirq handler 217 */ 218 enum trace_flag_type { 219 TRACE_FLAG_IRQS_OFF = 0x01, 220 TRACE_FLAG_IRQS_NOSUPPORT = 0x02, 221 TRACE_FLAG_NEED_RESCHED = 0x04, 222 TRACE_FLAG_HARDIRQ = 0x08, 223 TRACE_FLAG_SOFTIRQ = 0x10, 224 }; 225 226 #define TRACE_BUF_SIZE 1024 227 228 /* 229 * The CPU trace array - it consists of thousands of trace entries 230 * plus some other descriptor data: (for example which task started 231 * the trace, etc.) 232 */ 233 struct trace_array_cpu { 234 atomic_t disabled; 235 void *buffer_page; /* ring buffer spare */ 236 237 /* these fields get copied into max-trace: */ 238 unsigned long trace_idx; 239 unsigned long overrun; 240 unsigned long saved_latency; 241 unsigned long critical_start; 242 unsigned long critical_end; 243 unsigned long critical_sequence; 244 unsigned long nice; 245 unsigned long policy; 246 unsigned long rt_priority; 247 cycle_t preempt_timestamp; 248 pid_t pid; 249 uid_t uid; 250 char comm[TASK_COMM_LEN]; 251 }; 252 253 /* 254 * The trace array - an array of per-CPU trace arrays. This is the 255 * highest level data structure that individual tracers deal with. 256 * They have on/off state as well: 257 */ 258 struct trace_array { 259 struct ring_buffer *buffer; 260 unsigned long entries; 261 int cpu; 262 cycle_t time_start; 263 struct task_struct *waiter; 264 struct trace_array_cpu *data[NR_CPUS]; 265 }; 266 267 #define FTRACE_CMP_TYPE(var, type) \ 268 __builtin_types_compatible_p(typeof(var), type *) 269 270 #undef IF_ASSIGN 271 #define IF_ASSIGN(var, entry, etype, id) \ 272 if (FTRACE_CMP_TYPE(var, etype)) { \ 273 var = (typeof(var))(entry); \ 274 WARN_ON(id && (entry)->type != id); \ 275 break; \ 276 } 277 278 /* Will cause compile errors if type is not found. */ 279 extern void __ftrace_bad_type(void); 280 281 /* 282 * The trace_assign_type is a verifier that the entry type is 283 * the same as the type being assigned. To add new types simply 284 * add a line with the following format: 285 * 286 * IF_ASSIGN(var, ent, type, id); 287 * 288 * Where "type" is the trace type that includes the trace_entry 289 * as the "ent" item. And "id" is the trace identifier that is 290 * used in the trace_type enum. 291 * 292 * If the type can have more than one id, then use zero. 293 */ 294 #define trace_assign_type(var, ent) \ 295 do { \ 296 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \ 297 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \ 298 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \ 299 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\ 300 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \ 301 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \ 302 IF_ASSIGN(var, ent, struct special_entry, 0); \ 303 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ 304 TRACE_MMIO_RW); \ 305 IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ 306 TRACE_MMIO_MAP); \ 307 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\ 308 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\ 309 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \ 310 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \ 311 TRACE_GRAPH_ENT); \ 312 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ 313 TRACE_GRAPH_RET); \ 314 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\ 315 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \ 316 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry, \ 317 TRACE_KMEM_ALLOC); \ 318 IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \ 319 TRACE_KMEM_FREE); \ 320 __ftrace_bad_type(); \ 321 } while (0) 322 323 /* 324 * An option specific to a tracer. This is a boolean value. 325 * The bit is the bit index that sets its value on the 326 * flags value in struct tracer_flags. 327 */ 328 struct tracer_opt { 329 const char *name; /* Will appear on the trace_options file */ 330 u32 bit; /* Mask assigned in val field in tracer_flags */ 331 }; 332 333 /* 334 * The set of specific options for a tracer. Your tracer 335 * have to set the initial value of the flags val. 336 */ 337 struct tracer_flags { 338 u32 val; 339 struct tracer_opt *opts; 340 }; 341 342 /* Makes more easy to define a tracer opt */ 343 #define TRACER_OPT(s, b) .name = #s, .bit = b 344 345 346 /** 347 * struct tracer - a specific tracer and its callbacks to interact with debugfs 348 * @name: the name chosen to select it on the available_tracers file 349 * @init: called when one switches to this tracer (echo name > current_tracer) 350 * @reset: called when one switches to another tracer 351 * @start: called when tracing is unpaused (echo 1 > tracing_enabled) 352 * @stop: called when tracing is paused (echo 0 > tracing_enabled) 353 * @open: called when the trace file is opened 354 * @pipe_open: called when the trace_pipe file is opened 355 * @wait_pipe: override how the user waits for traces on trace_pipe 356 * @close: called when the trace file is released 357 * @read: override the default read callback on trace_pipe 358 * @splice_read: override the default splice_read callback on trace_pipe 359 * @selftest: selftest to run on boot (see trace_selftest.c) 360 * @print_headers: override the first lines that describe your columns 361 * @print_line: callback that prints a trace 362 * @set_flag: signals one of your private flags changed (trace_options file) 363 * @flags: your private flags 364 */ 365 struct tracer { 366 const char *name; 367 int (*init)(struct trace_array *tr); 368 void (*reset)(struct trace_array *tr); 369 void (*start)(struct trace_array *tr); 370 void (*stop)(struct trace_array *tr); 371 void (*open)(struct trace_iterator *iter); 372 void (*pipe_open)(struct trace_iterator *iter); 373 void (*wait_pipe)(struct trace_iterator *iter); 374 void (*close)(struct trace_iterator *iter); 375 ssize_t (*read)(struct trace_iterator *iter, 376 struct file *filp, char __user *ubuf, 377 size_t cnt, loff_t *ppos); 378 ssize_t (*splice_read)(struct trace_iterator *iter, 379 struct file *filp, 380 loff_t *ppos, 381 struct pipe_inode_info *pipe, 382 size_t len, 383 unsigned int flags); 384 #ifdef CONFIG_FTRACE_STARTUP_TEST 385 int (*selftest)(struct tracer *trace, 386 struct trace_array *tr); 387 #endif 388 void (*print_header)(struct seq_file *m); 389 enum print_line_t (*print_line)(struct trace_iterator *iter); 390 /* If you handled the flag setting, return 0 */ 391 int (*set_flag)(u32 old_flags, u32 bit, int set); 392 struct tracer *next; 393 int print_max; 394 struct tracer_flags *flags; 395 struct tracer_stat *stats; 396 }; 397 398 399 #define TRACE_PIPE_ALL_CPU -1 400 401 int tracer_init(struct tracer *t, struct trace_array *tr); 402 int tracing_is_enabled(void); 403 void trace_wake_up(void); 404 void tracing_reset(struct trace_array *tr, int cpu); 405 void tracing_reset_online_cpus(struct trace_array *tr); 406 void tracing_reset_current(int cpu); 407 void tracing_reset_current_online_cpus(void); 408 int tracing_open_generic(struct inode *inode, struct file *filp); 409 struct dentry *trace_create_file(const char *name, 410 mode_t mode, 411 struct dentry *parent, 412 void *data, 413 const struct file_operations *fops); 414 415 struct dentry *tracing_init_dentry(void); 416 void init_tracer_sysprof_debugfs(struct dentry *d_tracer); 417 418 struct ring_buffer_event; 419 420 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr, 421 int type, 422 unsigned long len, 423 unsigned long flags, 424 int pc); 425 void trace_buffer_unlock_commit(struct trace_array *tr, 426 struct ring_buffer_event *event, 427 unsigned long flags, int pc); 428 429 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, 430 struct trace_array_cpu *data); 431 432 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, 433 int *ent_cpu, u64 *ent_ts); 434 435 void default_wait_pipe(struct trace_iterator *iter); 436 void poll_wait_pipe(struct trace_iterator *iter); 437 438 void ftrace(struct trace_array *tr, 439 struct trace_array_cpu *data, 440 unsigned long ip, 441 unsigned long parent_ip, 442 unsigned long flags, int pc); 443 void tracing_sched_switch_trace(struct trace_array *tr, 444 struct task_struct *prev, 445 struct task_struct *next, 446 unsigned long flags, int pc); 447 448 void tracing_sched_wakeup_trace(struct trace_array *tr, 449 struct task_struct *wakee, 450 struct task_struct *cur, 451 unsigned long flags, int pc); 452 void trace_special(struct trace_array *tr, 453 struct trace_array_cpu *data, 454 unsigned long arg1, 455 unsigned long arg2, 456 unsigned long arg3, int pc); 457 void trace_function(struct trace_array *tr, 458 unsigned long ip, 459 unsigned long parent_ip, 460 unsigned long flags, int pc); 461 462 void trace_graph_return(struct ftrace_graph_ret *trace); 463 int trace_graph_entry(struct ftrace_graph_ent *trace); 464 void set_graph_array(struct trace_array *tr); 465 466 void tracing_start_cmdline_record(void); 467 void tracing_stop_cmdline_record(void); 468 void tracing_sched_switch_assign_trace(struct trace_array *tr); 469 void tracing_stop_sched_switch_record(void); 470 void tracing_start_sched_switch_record(void); 471 int register_tracer(struct tracer *type); 472 void unregister_tracer(struct tracer *type); 473 474 extern unsigned long nsecs_to_usecs(unsigned long nsecs); 475 476 extern unsigned long tracing_max_latency; 477 extern unsigned long tracing_thresh; 478 479 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu); 480 void update_max_tr_single(struct trace_array *tr, 481 struct task_struct *tsk, int cpu); 482 483 #ifdef CONFIG_STACKTRACE 484 void ftrace_trace_stack(struct trace_array *tr, unsigned long flags, 485 int skip, int pc); 486 487 void ftrace_trace_userstack(struct trace_array *tr, unsigned long flags, 488 int pc); 489 490 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, 491 int pc); 492 #else 493 static inline void ftrace_trace_stack(struct trace_array *tr, 494 unsigned long flags, int skip, int pc) 495 { 496 } 497 498 static inline void ftrace_trace_userstack(struct trace_array *tr, 499 unsigned long flags, int pc) 500 { 501 } 502 503 static inline void __trace_stack(struct trace_array *tr, unsigned long flags, 504 int skip, int pc) 505 { 506 } 507 #endif /* CONFIG_STACKTRACE */ 508 509 extern cycle_t ftrace_now(int cpu); 510 511 #ifdef CONFIG_CONTEXT_SWITCH_TRACER 512 typedef void 513 (*tracer_switch_func_t)(void *private, 514 void *__rq, 515 struct task_struct *prev, 516 struct task_struct *next); 517 518 struct tracer_switch_ops { 519 tracer_switch_func_t func; 520 void *private; 521 struct tracer_switch_ops *next; 522 }; 523 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */ 524 525 extern void trace_find_cmdline(int pid, char comm[]); 526 527 #ifdef CONFIG_DYNAMIC_FTRACE 528 extern unsigned long ftrace_update_tot_cnt; 529 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func 530 extern int DYN_FTRACE_TEST_NAME(void); 531 #endif 532 533 extern int ring_buffer_expanded; 534 extern bool tracing_selftest_disabled; 535 DECLARE_PER_CPU(local_t, ftrace_cpu_disabled); 536 537 #ifdef CONFIG_FTRACE_STARTUP_TEST 538 extern int trace_selftest_startup_function(struct tracer *trace, 539 struct trace_array *tr); 540 extern int trace_selftest_startup_function_graph(struct tracer *trace, 541 struct trace_array *tr); 542 extern int trace_selftest_startup_irqsoff(struct tracer *trace, 543 struct trace_array *tr); 544 extern int trace_selftest_startup_preemptoff(struct tracer *trace, 545 struct trace_array *tr); 546 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace, 547 struct trace_array *tr); 548 extern int trace_selftest_startup_wakeup(struct tracer *trace, 549 struct trace_array *tr); 550 extern int trace_selftest_startup_nop(struct tracer *trace, 551 struct trace_array *tr); 552 extern int trace_selftest_startup_sched_switch(struct tracer *trace, 553 struct trace_array *tr); 554 extern int trace_selftest_startup_sysprof(struct tracer *trace, 555 struct trace_array *tr); 556 extern int trace_selftest_startup_branch(struct tracer *trace, 557 struct trace_array *tr); 558 extern int trace_selftest_startup_hw_branches(struct tracer *trace, 559 struct trace_array *tr); 560 #endif /* CONFIG_FTRACE_STARTUP_TEST */ 561 562 extern void *head_page(struct trace_array_cpu *data); 563 extern unsigned long long ns2usecs(cycle_t nsec); 564 extern int 565 trace_vbprintk(unsigned long ip, const char *fmt, va_list args); 566 extern int 567 trace_vprintk(unsigned long ip, const char *fmt, va_list args); 568 569 extern unsigned long trace_flags; 570 571 /* Standard output formatting function used for function return traces */ 572 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 573 extern enum print_line_t print_graph_function(struct trace_iterator *iter); 574 extern enum print_line_t 575 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s); 576 577 #ifdef CONFIG_DYNAMIC_FTRACE 578 /* TODO: make this variable */ 579 #define FTRACE_GRAPH_MAX_FUNCS 32 580 extern int ftrace_graph_count; 581 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS]; 582 583 static inline int ftrace_graph_addr(unsigned long addr) 584 { 585 int i; 586 587 if (!ftrace_graph_count || test_tsk_trace_graph(current)) 588 return 1; 589 590 for (i = 0; i < ftrace_graph_count; i++) { 591 if (addr == ftrace_graph_funcs[i]) 592 return 1; 593 } 594 595 return 0; 596 } 597 #else 598 static inline int ftrace_trace_addr(unsigned long addr) 599 { 600 return 1; 601 } 602 static inline int ftrace_graph_addr(unsigned long addr) 603 { 604 return 1; 605 } 606 #endif /* CONFIG_DYNAMIC_FTRACE */ 607 #else /* CONFIG_FUNCTION_GRAPH_TRACER */ 608 static inline enum print_line_t 609 print_graph_function(struct trace_iterator *iter) 610 { 611 return TRACE_TYPE_UNHANDLED; 612 } 613 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 614 615 extern struct pid *ftrace_pid_trace; 616 617 #ifdef CONFIG_FUNCTION_TRACER 618 static inline int ftrace_trace_task(struct task_struct *task) 619 { 620 if (!ftrace_pid_trace) 621 return 1; 622 623 return test_tsk_trace_trace(task); 624 } 625 #else 626 static inline int ftrace_trace_task(struct task_struct *task) 627 { 628 return 1; 629 } 630 #endif 631 632 /* 633 * trace_iterator_flags is an enumeration that defines bit 634 * positions into trace_flags that controls the output. 635 * 636 * NOTE: These bits must match the trace_options array in 637 * trace.c. 638 */ 639 enum trace_iterator_flags { 640 TRACE_ITER_PRINT_PARENT = 0x01, 641 TRACE_ITER_SYM_OFFSET = 0x02, 642 TRACE_ITER_SYM_ADDR = 0x04, 643 TRACE_ITER_VERBOSE = 0x08, 644 TRACE_ITER_RAW = 0x10, 645 TRACE_ITER_HEX = 0x20, 646 TRACE_ITER_BIN = 0x40, 647 TRACE_ITER_BLOCK = 0x80, 648 TRACE_ITER_STACKTRACE = 0x100, 649 TRACE_ITER_SCHED_TREE = 0x200, 650 TRACE_ITER_PRINTK = 0x400, 651 TRACE_ITER_PREEMPTONLY = 0x800, 652 TRACE_ITER_BRANCH = 0x1000, 653 TRACE_ITER_ANNOTATE = 0x2000, 654 TRACE_ITER_USERSTACKTRACE = 0x4000, 655 TRACE_ITER_SYM_USEROBJ = 0x8000, 656 TRACE_ITER_PRINTK_MSGONLY = 0x10000, 657 TRACE_ITER_CONTEXT_INFO = 0x20000, /* Print pid/cpu/time */ 658 TRACE_ITER_LATENCY_FMT = 0x40000, 659 TRACE_ITER_GLOBAL_CLK = 0x80000, 660 TRACE_ITER_SLEEP_TIME = 0x100000, 661 TRACE_ITER_GRAPH_TIME = 0x200000, 662 }; 663 664 /* 665 * TRACE_ITER_SYM_MASK masks the options in trace_flags that 666 * control the output of kernel symbols. 667 */ 668 #define TRACE_ITER_SYM_MASK \ 669 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) 670 671 extern struct tracer nop_trace; 672 673 /** 674 * ftrace_preempt_disable - disable preemption scheduler safe 675 * 676 * When tracing can happen inside the scheduler, there exists 677 * cases that the tracing might happen before the need_resched 678 * flag is checked. If this happens and the tracer calls 679 * preempt_enable (after a disable), a schedule might take place 680 * causing an infinite recursion. 681 * 682 * To prevent this, we read the need_resched flag before 683 * disabling preemption. When we want to enable preemption we 684 * check the flag, if it is set, then we call preempt_enable_no_resched. 685 * Otherwise, we call preempt_enable. 686 * 687 * The rational for doing the above is that if need_resched is set 688 * and we have yet to reschedule, we are either in an atomic location 689 * (where we do not need to check for scheduling) or we are inside 690 * the scheduler and do not want to resched. 691 */ 692 static inline int ftrace_preempt_disable(void) 693 { 694 int resched; 695 696 resched = need_resched(); 697 preempt_disable_notrace(); 698 699 return resched; 700 } 701 702 /** 703 * ftrace_preempt_enable - enable preemption scheduler safe 704 * @resched: the return value from ftrace_preempt_disable 705 * 706 * This is a scheduler safe way to enable preemption and not miss 707 * any preemption checks. The disabled saved the state of preemption. 708 * If resched is set, then we are either inside an atomic or 709 * are inside the scheduler (we would have already scheduled 710 * otherwise). In this case, we do not want to call normal 711 * preempt_enable, but preempt_enable_no_resched instead. 712 */ 713 static inline void ftrace_preempt_enable(int resched) 714 { 715 if (resched) 716 preempt_enable_no_resched_notrace(); 717 else 718 preempt_enable_notrace(); 719 } 720 721 #ifdef CONFIG_BRANCH_TRACER 722 extern int enable_branch_tracing(struct trace_array *tr); 723 extern void disable_branch_tracing(void); 724 static inline int trace_branch_enable(struct trace_array *tr) 725 { 726 if (trace_flags & TRACE_ITER_BRANCH) 727 return enable_branch_tracing(tr); 728 return 0; 729 } 730 static inline void trace_branch_disable(void) 731 { 732 /* due to races, always disable */ 733 disable_branch_tracing(); 734 } 735 #else 736 static inline int trace_branch_enable(struct trace_array *tr) 737 { 738 return 0; 739 } 740 static inline void trace_branch_disable(void) 741 { 742 } 743 #endif /* CONFIG_BRANCH_TRACER */ 744 745 /* set ring buffers to default size if not already done so */ 746 int tracing_update_buffers(void); 747 748 /* trace event type bit fields, not numeric */ 749 enum { 750 TRACE_EVENT_TYPE_PRINTF = 1, 751 TRACE_EVENT_TYPE_RAW = 2, 752 }; 753 754 struct ftrace_event_field { 755 struct list_head link; 756 char *name; 757 char *type; 758 int offset; 759 int size; 760 int is_signed; 761 }; 762 763 struct event_filter { 764 int n_preds; 765 struct filter_pred **preds; 766 char *filter_string; 767 bool no_reset; 768 }; 769 770 struct event_subsystem { 771 struct list_head list; 772 const char *name; 773 struct dentry *entry; 774 struct event_filter *filter; 775 int nr_events; 776 }; 777 778 struct filter_pred; 779 780 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event, 781 int val1, int val2); 782 783 struct filter_pred { 784 filter_pred_fn_t fn; 785 u64 val; 786 char str_val[MAX_FILTER_STR_VAL]; 787 int str_len; 788 char *field_name; 789 int offset; 790 int not; 791 int op; 792 int pop_n; 793 }; 794 795 extern void print_event_filter(struct ftrace_event_call *call, 796 struct trace_seq *s); 797 extern int apply_event_filter(struct ftrace_event_call *call, 798 char *filter_string); 799 extern int apply_subsystem_event_filter(struct event_subsystem *system, 800 char *filter_string); 801 extern void print_subsystem_event_filter(struct event_subsystem *system, 802 struct trace_seq *s); 803 804 static inline int 805 filter_check_discard(struct ftrace_event_call *call, void *rec, 806 struct ring_buffer *buffer, 807 struct ring_buffer_event *event) 808 { 809 if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) { 810 ring_buffer_discard_commit(buffer, event); 811 return 1; 812 } 813 814 return 0; 815 } 816 817 #define DEFINE_COMPARISON_PRED(type) \ 818 static int filter_pred_##type(struct filter_pred *pred, void *event, \ 819 int val1, int val2) \ 820 { \ 821 type *addr = (type *)(event + pred->offset); \ 822 type val = (type)pred->val; \ 823 int match = 0; \ 824 \ 825 switch (pred->op) { \ 826 case OP_LT: \ 827 match = (*addr < val); \ 828 break; \ 829 case OP_LE: \ 830 match = (*addr <= val); \ 831 break; \ 832 case OP_GT: \ 833 match = (*addr > val); \ 834 break; \ 835 case OP_GE: \ 836 match = (*addr >= val); \ 837 break; \ 838 default: \ 839 break; \ 840 } \ 841 \ 842 return match; \ 843 } 844 845 #define DEFINE_EQUALITY_PRED(size) \ 846 static int filter_pred_##size(struct filter_pred *pred, void *event, \ 847 int val1, int val2) \ 848 { \ 849 u##size *addr = (u##size *)(event + pred->offset); \ 850 u##size val = (u##size)pred->val; \ 851 int match; \ 852 \ 853 match = (val == *addr) ^ pred->not; \ 854 \ 855 return match; \ 856 } 857 858 extern struct mutex event_mutex; 859 extern struct list_head ftrace_events; 860 861 extern const char *__start___trace_bprintk_fmt[]; 862 extern const char *__stop___trace_bprintk_fmt[]; 863 864 #undef TRACE_EVENT_FORMAT 865 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ 866 extern struct ftrace_event_call event_##call; 867 #undef TRACE_EVENT_FORMAT_NOFILTER 868 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt) 869 #include "trace_event_types.h" 870 871 #endif /* _LINUX_KERNEL_TRACE_H */ 872