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