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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_BOOT,
  26         TRACE_FN_RET,
  27
  28         __TRACE_LAST_TYPE
  29 };
  30
  31 /*
  32  * The trace entry - the most basic unit of tracing. This is what
  33  * is printed in the end as a single line in the trace output, such as:
  34  *
  35  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  36  */
  37 struct trace_entry {
  38         unsigned char           type;
  39         unsigned char           cpu;
  40         unsigned char           flags;
  41         unsigned char           preempt_count;
  42         int                     pid;
  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 return entry */
  55 struct ftrace_ret_entry {
  56         struct trace_entry      ent;
  57         unsigned long           ip;
  58         unsigned long           parent_ip;
  59         unsigned long long      calltime;
  60         unsigned long long      rettime;
  61 };
  62 extern struct tracer boot_tracer;
  63
  64 /*
  65  * Context switch trace entry - which task (and prio) we switched from/to:
  66  */
  67 struct ctx_switch_entry {
  68         struct trace_entry      ent;
  69         unsigned int            prev_pid;
  70         unsigned char           prev_prio;
  71         unsigned char           prev_state;
  72         unsigned int            next_pid;
  73         unsigned char           next_prio;
  74         unsigned char           next_state;
  75         unsigned int            next_cpu;
  76 };
  77
  78 /*
  79  * Special (free-form) trace entry:
  80  */
  81 struct special_entry {
  82         struct trace_entry      ent;
  83         unsigned long           arg1;
  84         unsigned long           arg2;
  85         unsigned long           arg3;
  86 };
  87
  88 /*
  89  * Stack-trace entry:
  90  */
  91
  92 #define FTRACE_STACK_ENTRIES    8
  93
  94 struct stack_entry {
  95         struct trace_entry      ent;
  96         unsigned long           caller[FTRACE_STACK_ENTRIES];
  97 };
  98
  99 /*
 100  * ftrace_printk entry:
 101  */
 102 struct print_entry {
 103         struct trace_entry      ent;
 104         unsigned long           ip;
 105         char                    buf[];
 106 };
 107
 108 #define TRACE_OLD_SIZE          88
 109
 110 struct trace_field_cont {
 111         unsigned char           type;
 112         /* Temporary till we get rid of this completely */
 113         char                    buf[TRACE_OLD_SIZE - 1];
 114 };
 115
 116 struct trace_mmiotrace_rw {
 117         struct trace_entry      ent;
 118         struct mmiotrace_rw     rw;
 119 };
 120
 121 struct trace_mmiotrace_map {
 122         struct trace_entry      ent;
 123         struct mmiotrace_map    map;
 124 };
 125
 126 struct trace_boot {
 127         struct trace_entry      ent;
 128         struct boot_trace       initcall;
 129 };
 130
 131 /*
 132  * trace_flag_type is an enumeration that holds different
 133  * states when a trace occurs. These are:
 134  *  IRQS_OFF            - interrupts were disabled
 135  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 136  *  NEED_RESCED         - reschedule is requested
 137  *  HARDIRQ             - inside an interrupt handler
 138  *  SOFTIRQ             - inside a softirq handler
 139  *  CONT                - multiple entries hold the trace item
 140  */
 141 enum trace_flag_type {
 142         TRACE_FLAG_IRQS_OFF             = 0x01,
 143         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 144         TRACE_FLAG_NEED_RESCHED         = 0x04,
 145         TRACE_FLAG_HARDIRQ              = 0x08,
 146         TRACE_FLAG_SOFTIRQ              = 0x10,
 147         TRACE_FLAG_CONT                 = 0x20,
 148 };
 149
 150 #define TRACE_BUF_SIZE          1024
 151
 152 /*
 153  * The CPU trace array - it consists of thousands of trace entries
 154  * plus some other descriptor data: (for example which task started
 155  * the trace, etc.)
 156  */
 157 struct trace_array_cpu {
 158         atomic_t                disabled;
 159
 160         /* these fields get copied into max-trace: */
 161         unsigned long           trace_idx;
 162         unsigned long           overrun;
 163         unsigned long           saved_latency;
 164         unsigned long           critical_start;
 165         unsigned long           critical_end;
 166         unsigned long           critical_sequence;
 167         unsigned long           nice;
 168         unsigned long           policy;
 169         unsigned long           rt_priority;
 170         cycle_t                 preempt_timestamp;
 171         pid_t                   pid;
 172         uid_t                   uid;
 173         char                    comm[TASK_COMM_LEN];
 174 };
 175
 176 struct trace_iterator;
 177
 178 /*
 179  * The trace array - an array of per-CPU trace arrays. This is the
 180  * highest level data structure that individual tracers deal with.
 181  * They have on/off state as well:
 182  */
 183 struct trace_array {
 184         struct ring_buffer      *buffer;
 185         unsigned long           entries;
 186         int                     cpu;
 187         cycle_t                 time_start;
 188         struct task_struct      *waiter;
 189         struct trace_array_cpu  *data[NR_CPUS];
 190 };
 191
 192 #define FTRACE_CMP_TYPE(var, type) \
 193         __builtin_types_compatible_p(typeof(var), type *)
 194
 195 #undef IF_ASSIGN
 196 #define IF_ASSIGN(var, entry, etype, id)                \
 197         if (FTRACE_CMP_TYPE(var, etype)) {              \
 198                 var = (typeof(var))(entry);             \
 199                 WARN_ON(id && (entry)->type != id);     \
 200                 break;                                  \
 201         }
 202
 203 /* Will cause compile errors if type is not found. */
 204 extern void __ftrace_bad_type(void);
 205
 206 /*
 207  * The trace_assign_type is a verifier that the entry type is
 208  * the same as the type being assigned. To add new types simply
 209  * add a line with the following format:
 210  *
 211  * IF_ASSIGN(var, ent, type, id);
 212  *
 213  *  Where "type" is the trace type that includes the trace_entry
 214  *  as the "ent" item. And "id" is the trace identifier that is
 215  *  used in the trace_type enum.
 216  *
 217  *  If the type can have more than one id, then use zero.
 218  */
 219 #define trace_assign_type(var, ent)                                     \
 220         do {                                                            \
 221                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 222                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 223                 IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
 224                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 225                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 226                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 227                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 228                           TRACE_MMIO_RW);                               \
 229                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 230                           TRACE_MMIO_MAP);                              \
 231                 IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT);     \
 232                 IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET); \
 233                 __ftrace_bad_type();                                    \
 234         } while (0)
 235
 236 /* Return values for print_line callback */
 237 enum print_line_t {
 238         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 239         TRACE_TYPE_HANDLED      = 1,
 240         TRACE_TYPE_UNHANDLED    = 2     /* Relay to other output functions */
 241 };
 242
 243 /*
 244  * A specific tracer, represented by methods that operate on a trace array:
 245  */
 246 struct tracer {
 247         const char              *name;
 248         void                    (*init)(struct trace_array *tr);
 249         void                    (*reset)(struct trace_array *tr);
 250         void                    (*start)(struct trace_array *tr);
 251         void                    (*stop)(struct trace_array *tr);
 252         void                    (*open)(struct trace_iterator *iter);
 253         void                    (*pipe_open)(struct trace_iterator *iter);
 254         void                    (*close)(struct trace_iterator *iter);
 255         ssize_t                 (*read)(struct trace_iterator *iter,
 256                                         struct file *filp, char __user *ubuf,
 257                                         size_t cnt, loff_t *ppos);
 258 #ifdef CONFIG_FTRACE_STARTUP_TEST
 259         int                     (*selftest)(struct tracer *trace,
 260                                             struct trace_array *tr);
 261 #endif
 262         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 263         struct tracer           *next;
 264         int                     print_max;
 265 };
 266
 267 struct trace_seq {
 268         unsigned char           buffer[PAGE_SIZE];
 269         unsigned int            len;
 270         unsigned int            readpos;
 271 };
 272
 273 /*
 274  * Trace iterator - used by printout routines who present trace
 275  * results to users and which routines might sleep, etc:
 276  */
 277 struct trace_iterator {
 278         struct trace_array      *tr;
 279         struct tracer           *trace;
 280         void                    *private;
 281         struct ring_buffer_iter *buffer_iter[NR_CPUS];
 282
 283         /* The below is zeroed out in pipe_read */
 284         struct trace_seq        seq;
 285         struct trace_entry      *ent;
 286         int                     cpu;
 287         u64                     ts;
 288
 289         unsigned long           iter_flags;
 290         loff_t                  pos;
 291         long                    idx;
 292
 293         cpumask_t               started;
 294 };
 295
 296 int tracing_is_enabled(void);
 297 void trace_wake_up(void);
 298 void tracing_reset(struct trace_array *tr, int cpu);
 299 int tracing_open_generic(struct inode *inode, struct file *filp);
 300 struct dentry *tracing_init_dentry(void);
 301 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 302
 303 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 304                                                 struct trace_array_cpu *data);
 305 void tracing_generic_entry_update(struct trace_entry *entry,
 306                                   unsigned long flags,
 307                                   int pc);
 308
 309 void ftrace(struct trace_array *tr,
 310                             struct trace_array_cpu *data,
 311                             unsigned long ip,
 312                             unsigned long parent_ip,
 313                             unsigned long flags, int pc);
 314 void tracing_sched_switch_trace(struct trace_array *tr,
 315                                 struct trace_array_cpu *data,
 316                                 struct task_struct *prev,
 317                                 struct task_struct *next,
 318                                 unsigned long flags, int pc);
 319 void tracing_record_cmdline(struct task_struct *tsk);
 320
 321 void tracing_sched_wakeup_trace(struct trace_array *tr,
 322                                 struct trace_array_cpu *data,
 323                                 struct task_struct *wakee,
 324                                 struct task_struct *cur,
 325                                 unsigned long flags, int pc);
 326 void trace_special(struct trace_array *tr,
 327                    struct trace_array_cpu *data,
 328                    unsigned long arg1,
 329                    unsigned long arg2,
 330                    unsigned long arg3, int pc);
 331 void trace_function(struct trace_array *tr,
 332                     struct trace_array_cpu *data,
 333                     unsigned long ip,
 334                     unsigned long parent_ip,
 335                     unsigned long flags, int pc);
 336 void
 337 trace_function_return(struct ftrace_retfunc *trace);
 338
 339 void tracing_start_cmdline_record(void);
 340 void tracing_stop_cmdline_record(void);
 341 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 342 void tracing_stop_sched_switch_record(void);
 343 void tracing_start_sched_switch_record(void);
 344 int register_tracer(struct tracer *type);
 345 void unregister_tracer(struct tracer *type);
 346
 347 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 348
 349 extern unsigned long tracing_max_latency;
 350 extern unsigned long tracing_thresh;
 351
 352 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 353 void update_max_tr_single(struct trace_array *tr,
 354                           struct task_struct *tsk, int cpu);
 355
 356 extern cycle_t ftrace_now(int cpu);
 357
 358 #ifdef CONFIG_FUNCTION_TRACER
 359 void tracing_start_function_trace(void);
 360 void tracing_stop_function_trace(void);
 361 #else
 362 # define tracing_start_function_trace()         do { } while (0)
 363 # define tracing_stop_function_trace()          do { } while (0)
 364 #endif
 365
 366 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 367 typedef void
 368 (*tracer_switch_func_t)(void *private,
 369                         void *__rq,
 370                         struct task_struct *prev,
 371                         struct task_struct *next);
 372
 373 struct tracer_switch_ops {
 374         tracer_switch_func_t            func;
 375         void                            *private;
 376         struct tracer_switch_ops        *next;
 377 };
 378
 379 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 380
 381 #ifdef CONFIG_DYNAMIC_FTRACE
 382 extern unsigned long ftrace_update_tot_cnt;
 383 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 384 extern int DYN_FTRACE_TEST_NAME(void);
 385 #endif
 386
 387 #ifdef CONFIG_FTRACE_STARTUP_TEST
 388 extern int trace_selftest_startup_function(struct tracer *trace,
 389                                            struct trace_array *tr);
 390 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 391                                           struct trace_array *tr);
 392 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 393                                              struct trace_array *tr);
 394 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 395                                                  struct trace_array *tr);
 396 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 397                                          struct trace_array *tr);
 398 extern int trace_selftest_startup_nop(struct tracer *trace,
 399                                          struct trace_array *tr);
 400 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 401                                                struct trace_array *tr);
 402 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 403                                                struct trace_array *tr);
 404 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 405
 406 extern void *head_page(struct trace_array_cpu *data);
 407 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
 408 extern void trace_seq_print_cont(struct trace_seq *s,
 409                                  struct trace_iterator *iter);
 410
 411 extern int
 412 seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
 413                 unsigned long sym_flags);
 414 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
 415                                  size_t cnt);
 416 extern long ns2usecs(cycle_t nsec);
 417 extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 418
 419 extern unsigned long trace_flags;
 420
 421 /* Standard output formatting function used for function return traces */
 422 #ifdef CONFIG_FUNCTION_RET_TRACER
 423 extern enum print_line_t print_return_function(struct trace_iterator *iter);
 424 #else
 425 static inline enum print_line_t
 426 print_return_function(struct trace_iterator *iter)
 427 {
 428         return TRACE_TYPE_UNHANDLED;
 429 }
 430 #endif
 431
 432 /*
 433  * trace_iterator_flags is an enumeration that defines bit
 434  * positions into trace_flags that controls the output.
 435  *
 436  * NOTE: These bits must match the trace_options array in
 437  *       trace.c.
 438  */
 439 enum trace_iterator_flags {
 440         TRACE_ITER_PRINT_PARENT         = 0x01,
 441         TRACE_ITER_SYM_OFFSET           = 0x02,
 442         TRACE_ITER_SYM_ADDR             = 0x04,
 443         TRACE_ITER_VERBOSE              = 0x08,
 444         TRACE_ITER_RAW                  = 0x10,
 445         TRACE_ITER_HEX                  = 0x20,
 446         TRACE_ITER_BIN                  = 0x40,
 447         TRACE_ITER_BLOCK                = 0x80,
 448         TRACE_ITER_STACKTRACE           = 0x100,
 449         TRACE_ITER_SCHED_TREE           = 0x200,
 450         TRACE_ITER_PRINTK               = 0x400,
 451         TRACE_ITER_PREEMPTONLY          = 0x800,
 452 };
 453
 454 /*
 455  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 456  * control the output of kernel symbols.
 457  */
 458 #define TRACE_ITER_SYM_MASK \
 459         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 460
 461 extern struct tracer nop_trace;
 462
 463 /**
 464  * ftrace_preempt_disable - disable preemption scheduler safe
 465  *
 466  * When tracing can happen inside the scheduler, there exists
 467  * cases that the tracing might happen before the need_resched
 468  * flag is checked. If this happens and the tracer calls
 469  * preempt_enable (after a disable), a schedule might take place
 470  * causing an infinite recursion.
 471  *
 472  * To prevent this, we read the need_recshed flag before
 473  * disabling preemption. When we want to enable preemption we
 474  * check the flag, if it is set, then we call preempt_enable_no_resched.
 475  * Otherwise, we call preempt_enable.
 476  *
 477  * The rational for doing the above is that if need resched is set
 478  * and we have yet to reschedule, we are either in an atomic location
 479  * (where we do not need to check for scheduling) or we are inside
 480  * the scheduler and do not want to resched.
 481  */
 482 static inline int ftrace_preempt_disable(void)
 483 {
 484         int resched;
 485
 486         resched = need_resched();
 487         preempt_disable_notrace();
 488
 489         return resched;
 490 }
 491
 492 /**
 493  * ftrace_preempt_enable - enable preemption scheduler safe
 494  * @resched: the return value from ftrace_preempt_disable
 495  *
 496  * This is a scheduler safe way to enable preemption and not miss
 497  * any preemption checks. The disabled saved the state of preemption.
 498  * If resched is set, then we were either inside an atomic or
 499  * are inside the scheduler (we would have already scheduled
 500  * otherwise). In this case, we do not want to call normal
 501  * preempt_enable, but preempt_enable_no_resched instead.
 502  */
 503 static inline void ftrace_preempt_enable(int resched)
 504 {
 505         if (resched)
 506                 preempt_enable_no_resched_notrace();
 507         else
 508                 preempt_enable_notrace();
 509 }
 510
 511 #endif /* _LINUX_KERNEL_TRACE_H */