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 13 enum trace_type { 14 __TRACE_FIRST_TYPE = 0, 15 16 TRACE_FN, 17 TRACE_CTX, 18 TRACE_WAKE, 19 TRACE_CONT, 20 TRACE_STACK, 21 TRACE_PRINT, 22 TRACE_SPECIAL, 23 TRACE_MMIO_RW, 24 TRACE_MMIO_MAP, 25 TRACE_BRANCH, 26 TRACE_BOOT_CALL, 27 TRACE_BOOT_RET, 28 TRACE_GRAPH_RET, 29 TRACE_GRAPH_ENT, 30 TRACE_USER_STACK, 31 TRACE_HW_BRANCHES, 32 TRACE_POWER, 33 34 __TRACE_LAST_TYPE 35 }; 36 37 /* 38 * The trace entry - the most basic unit of tracing. This is what 39 * is printed in the end as a single line in the trace output, such as: 40 * 41 * bash-15816 [01] 235.197585: idle_cpu <- irq_enter 42 */ 43 struct trace_entry { 44 unsigned char type; 45 unsigned char cpu; 46 unsigned char flags; 47 unsigned char preempt_count; 48 int pid; 49 int tgid; 50 }; 51 52 /* 53 * Function trace entry - function address and parent function addres: 54 */ 55 struct ftrace_entry { 56 struct trace_entry ent; 57 unsigned long ip; 58 unsigned long parent_ip; 59 }; 60 61 /* Function call entry */ 62 struct ftrace_graph_ent_entry { 63 struct trace_entry ent; 64 struct ftrace_graph_ent graph_ent; 65 }; 66 67 /* Function return entry */ 68 struct ftrace_graph_ret_entry { 69 struct trace_entry ent; 70 struct ftrace_graph_ret ret; 71 }; 72 extern struct tracer boot_tracer; 73 74 /* 75 * Context switch trace entry - which task (and prio) we switched from/to: 76 */ 77 struct ctx_switch_entry { 78 struct trace_entry ent; 79 unsigned int prev_pid; 80 unsigned char prev_prio; 81 unsigned char prev_state; 82 unsigned int next_pid; 83 unsigned char next_prio; 84 unsigned char next_state; 85 unsigned int next_cpu; 86 }; 87 88 /* 89 * Special (free-form) trace entry: 90 */ 91 struct special_entry { 92 struct trace_entry ent; 93 unsigned long arg1; 94 unsigned long arg2; 95 unsigned long arg3; 96 }; 97 98 /* 99 * Stack-trace entry: 100 */ 101 102 #define FTRACE_STACK_ENTRIES 8 103 104 struct stack_entry { 105 struct trace_entry ent; 106 unsigned long caller[FTRACE_STACK_ENTRIES]; 107 }; 108 109 struct userstack_entry { 110 struct trace_entry ent; 111 unsigned long caller[FTRACE_STACK_ENTRIES]; 112 }; 113 114 /* 115 * ftrace_printk entry: 116 */ 117 struct print_entry { 118 struct trace_entry ent; 119 unsigned long ip; 120 int depth; 121 char buf[]; 122 }; 123 124 #define TRACE_OLD_SIZE 88 125 126 struct trace_field_cont { 127 unsigned char type; 128 /* Temporary till we get rid of this completely */ 129 char buf[TRACE_OLD_SIZE - 1]; 130 }; 131 132 struct trace_mmiotrace_rw { 133 struct trace_entry ent; 134 struct mmiotrace_rw rw; 135 }; 136 137 struct trace_mmiotrace_map { 138 struct trace_entry ent; 139 struct mmiotrace_map map; 140 }; 141 142 struct trace_boot_call { 143 struct trace_entry ent; 144 struct boot_trace_call boot_call; 145 }; 146 147 struct trace_boot_ret { 148 struct trace_entry ent; 149 struct boot_trace_ret boot_ret; 150 }; 151 152 #define TRACE_FUNC_SIZE 30 153 #define TRACE_FILE_SIZE 20 154 struct trace_branch { 155 struct trace_entry ent; 156 unsigned line; 157 char func[TRACE_FUNC_SIZE+1]; 158 char file[TRACE_FILE_SIZE+1]; 159 char correct; 160 }; 161 162 struct hw_branch_entry { 163 struct trace_entry ent; 164 u64 from; 165 u64 to; 166 }; 167 168 struct trace_power { 169 struct trace_entry ent; 170 struct power_trace state_data; 171 }; 172 173 /* 174 * trace_flag_type is an enumeration that holds different 175 * states when a trace occurs. These are: 176 * IRQS_OFF - interrupts were disabled 177 * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags 178 * NEED_RESCED - reschedule is requested 179 * HARDIRQ - inside an interrupt handler 180 * SOFTIRQ - inside a softirq handler 181 * CONT - multiple entries hold the trace item 182 */ 183 enum trace_flag_type { 184 TRACE_FLAG_IRQS_OFF = 0x01, 185 TRACE_FLAG_IRQS_NOSUPPORT = 0x02, 186 TRACE_FLAG_NEED_RESCHED = 0x04, 187 TRACE_FLAG_HARDIRQ = 0x08, 188 TRACE_FLAG_SOFTIRQ = 0x10, 189 TRACE_FLAG_CONT = 0x20, 190 }; 191 192 #define TRACE_BUF_SIZE 1024 193 194 /* 195 * The CPU trace array - it consists of thousands of trace entries 196 * plus some other descriptor data: (for example which task started 197 * the trace, etc.) 198 */ 199 struct trace_array_cpu { 200 atomic_t disabled; 201 202 /* these fields get copied into max-trace: */ 203 unsigned long trace_idx; 204 unsigned long overrun; 205 unsigned long saved_latency; 206 unsigned long critical_start; 207 unsigned long critical_end; 208 unsigned long critical_sequence; 209 unsigned long nice; 210 unsigned long policy; 211 unsigned long rt_priority; 212 cycle_t preempt_timestamp; 213 pid_t pid; 214 uid_t uid; 215 char comm[TASK_COMM_LEN]; 216 }; 217 218 struct trace_iterator; 219 220 /* 221 * The trace array - an array of per-CPU trace arrays. This is the 222 * highest level data structure that individual tracers deal with. 223 * They have on/off state as well: 224 */ 225 struct trace_array { 226 struct ring_buffer *buffer; 227 unsigned long entries; 228 int cpu; 229 cycle_t time_start; 230 struct task_struct *waiter; 231 struct trace_array_cpu *data[NR_CPUS]; 232 }; 233 234 #define FTRACE_CMP_TYPE(var, type) \ 235 __builtin_types_compatible_p(typeof(var), type *) 236 237 #undef IF_ASSIGN 238 #define IF_ASSIGN(var, entry, etype, id) \ 239 if (FTRACE_CMP_TYPE(var, etype)) { \ 240 var = (typeof(var))(entry); \ 241 WARN_ON(id && (entry)->type != id); \ 242 break; \ 243 } 244 245 /* Will cause compile errors if type is not found. */ 246 extern void __ftrace_bad_type(void); 247 248 /* 249 * The trace_assign_type is a verifier that the entry type is 250 * the same as the type being assigned. To add new types simply 251 * add a line with the following format: 252 * 253 * IF_ASSIGN(var, ent, type, id); 254 * 255 * Where "type" is the trace type that includes the trace_entry 256 * as the "ent" item. And "id" is the trace identifier that is 257 * used in the trace_type enum. 258 * 259 * If the type can have more than one id, then use zero. 260 */ 261 #define trace_assign_type(var, ent) \ 262 do { \ 263 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \ 264 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \ 265 IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \ 266 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \ 267 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\ 268 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \ 269 IF_ASSIGN(var, ent, struct special_entry, 0); \ 270 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ 271 TRACE_MMIO_RW); \ 272 IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ 273 TRACE_MMIO_MAP); \ 274 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\ 275 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\ 276 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \ 277 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \ 278 TRACE_GRAPH_ENT); \ 279 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ 280 TRACE_GRAPH_RET); \ 281 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\ 282 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \ 283 __ftrace_bad_type(); \ 284 } while (0) 285 286 /* Return values for print_line callback */ 287 enum print_line_t { 288 TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */ 289 TRACE_TYPE_HANDLED = 1, 290 TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */ 291 }; 292 293 294 /* 295 * An option specific to a tracer. This is a boolean value. 296 * The bit is the bit index that sets its value on the 297 * flags value in struct tracer_flags. 298 */ 299 struct tracer_opt { 300 const char *name; /* Will appear on the trace_options file */ 301 u32 bit; /* Mask assigned in val field in tracer_flags */ 302 }; 303 304 /* 305 * The set of specific options for a tracer. Your tracer 306 * have to set the initial value of the flags val. 307 */ 308 struct tracer_flags { 309 u32 val; 310 struct tracer_opt *opts; 311 }; 312 313 /* Makes more easy to define a tracer opt */ 314 #define TRACER_OPT(s, b) .name = #s, .bit = b 315 316 /* 317 * A specific tracer, represented by methods that operate on a trace array: 318 */ 319 struct tracer { 320 const char *name; 321 /* Your tracer should raise a warning if init fails */ 322 int (*init)(struct trace_array *tr); 323 void (*reset)(struct trace_array *tr); 324 void (*start)(struct trace_array *tr); 325 void (*stop)(struct trace_array *tr); 326 void (*open)(struct trace_iterator *iter); 327 void (*pipe_open)(struct trace_iterator *iter); 328 void (*close)(struct trace_iterator *iter); 329 ssize_t (*read)(struct trace_iterator *iter, 330 struct file *filp, char __user *ubuf, 331 size_t cnt, loff_t *ppos); 332 #ifdef CONFIG_FTRACE_STARTUP_TEST 333 int (*selftest)(struct tracer *trace, 334 struct trace_array *tr); 335 #endif 336 void (*print_header)(struct seq_file *m); 337 enum print_line_t (*print_line)(struct trace_iterator *iter); 338 /* If you handled the flag setting, return 0 */ 339 int (*set_flag)(u32 old_flags, u32 bit, int set); 340 struct tracer *next; 341 int print_max; 342 struct tracer_flags *flags; 343 }; 344 345 struct trace_seq { 346 unsigned char buffer[PAGE_SIZE]; 347 unsigned int len; 348 unsigned int readpos; 349 }; 350 351 /* 352 * Trace iterator - used by printout routines who present trace 353 * results to users and which routines might sleep, etc: 354 */ 355 struct trace_iterator { 356 struct trace_array *tr; 357 struct tracer *trace; 358 void *private; 359 struct ring_buffer_iter *buffer_iter[NR_CPUS]; 360 361 /* The below is zeroed out in pipe_read */ 362 struct trace_seq seq; 363 struct trace_entry *ent; 364 int cpu; 365 u64 ts; 366 367 unsigned long iter_flags; 368 loff_t pos; 369 long idx; 370 371 cpumask_var_t started; 372 }; 373 374 int tracing_is_enabled(void); 375 void trace_wake_up(void); 376 void tracing_reset(struct trace_array *tr, int cpu); 377 void tracing_reset_online_cpus(struct trace_array *tr); 378 int tracing_open_generic(struct inode *inode, struct file *filp); 379 struct dentry *tracing_init_dentry(void); 380 void init_tracer_sysprof_debugfs(struct dentry *d_tracer); 381 382 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, 383 struct trace_array_cpu *data); 384 void tracing_generic_entry_update(struct trace_entry *entry, 385 unsigned long flags, 386 int pc); 387 388 void ftrace(struct trace_array *tr, 389 struct trace_array_cpu *data, 390 unsigned long ip, 391 unsigned long parent_ip, 392 unsigned long flags, int pc); 393 void tracing_sched_switch_trace(struct trace_array *tr, 394 struct trace_array_cpu *data, 395 struct task_struct *prev, 396 struct task_struct *next, 397 unsigned long flags, int pc); 398 void tracing_record_cmdline(struct task_struct *tsk); 399 400 void tracing_sched_wakeup_trace(struct trace_array *tr, 401 struct trace_array_cpu *data, 402 struct task_struct *wakee, 403 struct task_struct *cur, 404 unsigned long flags, int pc); 405 void trace_special(struct trace_array *tr, 406 struct trace_array_cpu *data, 407 unsigned long arg1, 408 unsigned long arg2, 409 unsigned long arg3, int pc); 410 void trace_function(struct trace_array *tr, 411 struct trace_array_cpu *data, 412 unsigned long ip, 413 unsigned long parent_ip, 414 unsigned long flags, int pc); 415 416 void trace_graph_return(struct ftrace_graph_ret *trace); 417 int trace_graph_entry(struct ftrace_graph_ent *trace); 418 void trace_hw_branch(struct trace_array *tr, u64 from, u64 to); 419 420 void tracing_start_cmdline_record(void); 421 void tracing_stop_cmdline_record(void); 422 void tracing_sched_switch_assign_trace(struct trace_array *tr); 423 void tracing_stop_sched_switch_record(void); 424 void tracing_start_sched_switch_record(void); 425 int register_tracer(struct tracer *type); 426 void unregister_tracer(struct tracer *type); 427 428 extern unsigned long nsecs_to_usecs(unsigned long nsecs); 429 430 extern unsigned long tracing_max_latency; 431 extern unsigned long tracing_thresh; 432 433 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu); 434 void update_max_tr_single(struct trace_array *tr, 435 struct task_struct *tsk, int cpu); 436 437 extern cycle_t ftrace_now(int cpu); 438 439 #ifdef CONFIG_FUNCTION_TRACER 440 void tracing_start_function_trace(void); 441 void tracing_stop_function_trace(void); 442 #else 443 # define tracing_start_function_trace() do { } while (0) 444 # define tracing_stop_function_trace() do { } while (0) 445 #endif 446 447 #ifdef CONFIG_CONTEXT_SWITCH_TRACER 448 typedef void 449 (*tracer_switch_func_t)(void *private, 450 void *__rq, 451 struct task_struct *prev, 452 struct task_struct *next); 453 454 struct tracer_switch_ops { 455 tracer_switch_func_t func; 456 void *private; 457 struct tracer_switch_ops *next; 458 }; 459 460 char *trace_find_cmdline(int pid); 461 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */ 462 463 #ifdef CONFIG_DYNAMIC_FTRACE 464 extern unsigned long ftrace_update_tot_cnt; 465 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func 466 extern int DYN_FTRACE_TEST_NAME(void); 467 #endif 468 469 #ifdef CONFIG_FTRACE_STARTUP_TEST 470 extern int trace_selftest_startup_function(struct tracer *trace, 471 struct trace_array *tr); 472 extern int trace_selftest_startup_irqsoff(struct tracer *trace, 473 struct trace_array *tr); 474 extern int trace_selftest_startup_preemptoff(struct tracer *trace, 475 struct trace_array *tr); 476 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace, 477 struct trace_array *tr); 478 extern int trace_selftest_startup_wakeup(struct tracer *trace, 479 struct trace_array *tr); 480 extern int trace_selftest_startup_nop(struct tracer *trace, 481 struct trace_array *tr); 482 extern int trace_selftest_startup_sched_switch(struct tracer *trace, 483 struct trace_array *tr); 484 extern int trace_selftest_startup_sysprof(struct tracer *trace, 485 struct trace_array *tr); 486 extern int trace_selftest_startup_branch(struct tracer *trace, 487 struct trace_array *tr); 488 #endif /* CONFIG_FTRACE_STARTUP_TEST */ 489 490 extern void *head_page(struct trace_array_cpu *data); 491 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...); 492 extern void trace_seq_print_cont(struct trace_seq *s, 493 struct trace_iterator *iter); 494 495 extern int 496 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, 497 unsigned long sym_flags); 498 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, 499 size_t cnt); 500 extern long ns2usecs(cycle_t nsec); 501 extern int 502 trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args); 503 504 extern unsigned long trace_flags; 505 506 /* Standard output formatting function used for function return traces */ 507 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 508 extern enum print_line_t print_graph_function(struct trace_iterator *iter); 509 510 #ifdef CONFIG_DYNAMIC_FTRACE 511 /* TODO: make this variable */ 512 #define FTRACE_GRAPH_MAX_FUNCS 32 513 extern int ftrace_graph_count; 514 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS]; 515 516 static inline int ftrace_graph_addr(unsigned long addr) 517 { 518 int i; 519 520 if (!ftrace_graph_count || test_tsk_trace_graph(current)) 521 return 1; 522 523 for (i = 0; i < ftrace_graph_count; i++) { 524 if (addr == ftrace_graph_funcs[i]) 525 return 1; 526 } 527 528 return 0; 529 } 530 #else 531 static inline int ftrace_trace_addr(unsigned long addr) 532 { 533 return 1; 534 } 535 static inline int ftrace_graph_addr(unsigned long addr) 536 { 537 return 1; 538 } 539 #endif /* CONFIG_DYNAMIC_FTRACE */ 540 541 #else /* CONFIG_FUNCTION_GRAPH_TRACER */ 542 static inline enum print_line_t 543 print_graph_function(struct trace_iterator *iter) 544 { 545 return TRACE_TYPE_UNHANDLED; 546 } 547 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 548 549 extern struct pid *ftrace_pid_trace; 550 551 static inline int ftrace_trace_task(struct task_struct *task) 552 { 553 if (!ftrace_pid_trace) 554 return 1; 555 556 return test_tsk_trace_trace(task); 557 } 558 559 /* 560 * trace_iterator_flags is an enumeration that defines bit 561 * positions into trace_flags that controls the output. 562 * 563 * NOTE: These bits must match the trace_options array in 564 * trace.c. 565 */ 566 enum trace_iterator_flags { 567 TRACE_ITER_PRINT_PARENT = 0x01, 568 TRACE_ITER_SYM_OFFSET = 0x02, 569 TRACE_ITER_SYM_ADDR = 0x04, 570 TRACE_ITER_VERBOSE = 0x08, 571 TRACE_ITER_RAW = 0x10, 572 TRACE_ITER_HEX = 0x20, 573 TRACE_ITER_BIN = 0x40, 574 TRACE_ITER_BLOCK = 0x80, 575 TRACE_ITER_STACKTRACE = 0x100, 576 TRACE_ITER_SCHED_TREE = 0x200, 577 TRACE_ITER_PRINTK = 0x400, 578 TRACE_ITER_PREEMPTONLY = 0x800, 579 TRACE_ITER_BRANCH = 0x1000, 580 TRACE_ITER_ANNOTATE = 0x2000, 581 TRACE_ITER_USERSTACKTRACE = 0x4000, 582 TRACE_ITER_SYM_USEROBJ = 0x8000, 583 TRACE_ITER_PRINTK_MSGONLY = 0x10000 584 }; 585 586 /* 587 * TRACE_ITER_SYM_MASK masks the options in trace_flags that 588 * control the output of kernel symbols. 589 */ 590 #define TRACE_ITER_SYM_MASK \ 591 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) 592 593 extern struct tracer nop_trace; 594 595 /** 596 * ftrace_preempt_disable - disable preemption scheduler safe 597 * 598 * When tracing can happen inside the scheduler, there exists 599 * cases that the tracing might happen before the need_resched 600 * flag is checked. If this happens and the tracer calls 601 * preempt_enable (after a disable), a schedule might take place 602 * causing an infinite recursion. 603 * 604 * To prevent this, we read the need_recshed flag before 605 * disabling preemption. When we want to enable preemption we 606 * check the flag, if it is set, then we call preempt_enable_no_resched. 607 * Otherwise, we call preempt_enable. 608 * 609 * The rational for doing the above is that if need resched is set 610 * and we have yet to reschedule, we are either in an atomic location 611 * (where we do not need to check for scheduling) or we are inside 612 * the scheduler and do not want to resched. 613 */ 614 static inline int ftrace_preempt_disable(void) 615 { 616 int resched; 617 618 resched = need_resched(); 619 preempt_disable_notrace(); 620 621 return resched; 622 } 623 624 /** 625 * ftrace_preempt_enable - enable preemption scheduler safe 626 * @resched: the return value from ftrace_preempt_disable 627 * 628 * This is a scheduler safe way to enable preemption and not miss 629 * any preemption checks. The disabled saved the state of preemption. 630 * If resched is set, then we were either inside an atomic or 631 * are inside the scheduler (we would have already scheduled 632 * otherwise). In this case, we do not want to call normal 633 * preempt_enable, but preempt_enable_no_resched instead. 634 */ 635 static inline void ftrace_preempt_enable(int resched) 636 { 637 if (resched) 638 preempt_enable_no_resched_notrace(); 639 else 640 preempt_enable_notrace(); 641 } 642 643 #ifdef CONFIG_BRANCH_TRACER 644 extern int enable_branch_tracing(struct trace_array *tr); 645 extern void disable_branch_tracing(void); 646 static inline int trace_branch_enable(struct trace_array *tr) 647 { 648 if (trace_flags & TRACE_ITER_BRANCH) 649 return enable_branch_tracing(tr); 650 return 0; 651 } 652 static inline void trace_branch_disable(void) 653 { 654 /* due to races, always disable */ 655 disable_branch_tracing(); 656 } 657 #else 658 static inline int trace_branch_enable(struct trace_array *tr) 659 { 660 return 0; 661 } 662 static inline void trace_branch_disable(void) 663 { 664 } 665 #endif /* CONFIG_BRANCH_TRACER */ 666 667 #endif /* _LINUX_KERNEL_TRACE_H */ 668