kernel/trace/trace.h

   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
  12 enum trace_type {
  13         __TRACE_FIRST_TYPE = 0,
  14
  15         TRACE_FN,
  16         TRACE_CTX,
  17         TRACE_WAKE,
  18         TRACE_CONT,
  19         TRACE_STACK,
  20         TRACE_PRINT,
  21         TRACE_SPECIAL,
  22         TRACE_MMIO_RW,
  23         TRACE_MMIO_MAP,
  24         TRACE_BOOT,
  25
  26         __TRACE_LAST_TYPE
  27 };
  28
  29 /*
  30  * The trace entry - the most basic unit of tracing. This is what
  31  * is printed in the end as a single line in the trace output, such as:
  32  *
  33  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  34  */
  35 struct trace_entry {
  36         unsigned char           type;
  37         unsigned char           cpu;
  38         unsigned char           flags;
  39         unsigned char           preempt_count;
  40         int                     pid;
  41 };
  42
  43 /*
  44  * Function trace entry - function address and parent function addres:
  45  */
  46 struct ftrace_entry {
  47         struct trace_entry      ent;
  48         unsigned long           ip;
  49         unsigned long           parent_ip;
  50 };
  51 extern struct tracer boot_tracer;
  52
  53 /*
  54  * Context switch trace entry - which task (and prio) we switched from/to:
  55  */
  56 struct ctx_switch_entry {
  57         struct trace_entry      ent;
  58         unsigned int            prev_pid;
  59         unsigned char           prev_prio;
  60         unsigned char           prev_state;
  61         unsigned int            next_pid;
  62         unsigned char           next_prio;
  63         unsigned char           next_state;
  64         unsigned int            next_cpu;
  65 };
  66
  67 /*
  68  * Special (free-form) trace entry:
  69  */
  70 struct special_entry {
  71         struct trace_entry      ent;
  72         unsigned long           arg1;
  73         unsigned long           arg2;
  74         unsigned long           arg3;
  75 };
  76
  77 /*
  78  * Stack-trace entry:
  79  */
  80
  81 #define FTRACE_STACK_ENTRIES    8
  82
  83 struct stack_entry {
  84         struct trace_entry      ent;
  85         unsigned long           caller[FTRACE_STACK_ENTRIES];
  86 };
  87
  88 /*
  89  * ftrace_printk entry:
  90  */
  91 struct print_entry {
  92         struct trace_entry      ent;
  93         unsigned long           ip;
  94         char                    buf[];
  95 };
  96
  97 #define TRACE_OLD_SIZE          88
  98
  99 struct trace_field_cont {
 100         unsigned char           type;
 101         /* Temporary till we get rid of this completely */
 102         char                    buf[TRACE_OLD_SIZE - 1];
 103 };
 104
 105 struct trace_mmiotrace_rw {
 106         struct trace_entry      ent;
 107         struct mmiotrace_rw     rw;
 108 };
 109
 110 struct trace_mmiotrace_map {
 111         struct trace_entry      ent;
 112         struct mmiotrace_map    map;
 113 };
 114
 115 struct trace_boot {
 116         struct trace_entry      ent;
 117         struct boot_trace       initcall;
 118 };
 119
 120 /*
 121  * trace_flag_type is an enumeration that holds different
 122  * states when a trace occurs. These are:
 123  *  IRQS_OFF    - interrupts were disabled
 124  *  NEED_RESCED - reschedule is requested
 125  *  HARDIRQ     - inside an interrupt handler
 126  *  SOFTIRQ     - inside a softirq handler
 127  *  CONT        - multiple entries hold the trace item
 128  */
 129 enum trace_flag_type {
 130         TRACE_FLAG_IRQS_OFF             = 0x01,
 131         TRACE_FLAG_NEED_RESCHED         = 0x02,
 132         TRACE_FLAG_HARDIRQ              = 0x04,
 133         TRACE_FLAG_SOFTIRQ              = 0x08,
 134         TRACE_FLAG_CONT                 = 0x10,
 135 };
 136
 137 #define TRACE_BUF_SIZE          1024
 138
 139 /*
 140  * The CPU trace array - it consists of thousands of trace entries
 141  * plus some other descriptor data: (for example which task started
 142  * the trace, etc.)
 143  */
 144 struct trace_array_cpu {
 145         atomic_t                disabled;
 146
 147         /* these fields get copied into max-trace: */
 148         unsigned long           trace_idx;
 149         unsigned long           overrun;
 150         unsigned long           saved_latency;
 151         unsigned long           critical_start;
 152         unsigned long           critical_end;
 153         unsigned long           critical_sequence;
 154         unsigned long           nice;
 155         unsigned long           policy;
 156         unsigned long           rt_priority;
 157         cycle_t                 preempt_timestamp;
 158         pid_t                   pid;
 159         uid_t                   uid;
 160         char                    comm[TASK_COMM_LEN];
 161 };
 162
 163 struct trace_iterator;
 164
 165 /*
 166  * The trace array - an array of per-CPU trace arrays. This is the
 167  * highest level data structure that individual tracers deal with.
 168  * They have on/off state as well:
 169  */
 170 struct trace_array {
 171         struct ring_buffer      *buffer;
 172         unsigned long           entries;
 173         long                    ctrl;
 174         int                     cpu;
 175         cycle_t                 time_start;
 176         struct task_struct      *waiter;
 177         struct trace_array_cpu  *data[NR_CPUS];
 178 };
 179
 180 #define FTRACE_CMP_TYPE(var, type) \
 181         __builtin_types_compatible_p(typeof(var), type *)
 182
 183 #undef IF_ASSIGN
 184 #define IF_ASSIGN(var, entry, etype, id)                \
 185         if (FTRACE_CMP_TYPE(var, etype)) {              \
 186                 var = (typeof(var))(entry);             \
 187                 WARN_ON(id && (entry)->type != id);     \
 188                 break;                                  \
 189         }
 190
 191 /* Will cause compile errors if type is not found. */
 192 extern void __ftrace_bad_type(void);
 193
 194 /*
 195  * The trace_assign_type is a verifier that the entry type is
 196  * the same as the type being assigned. To add new types simply
 197  * add a line with the following format:
 198  *
 199  * IF_ASSIGN(var, ent, type, id);
 200  *
 201  *  Where "type" is the trace type that includes the trace_entry
 202  *  as the "ent" item. And "id" is the trace identifier that is
 203  *  used in the trace_type enum.
 204  *
 205  *  If the type can have more than one id, then use zero.
 206  */
 207 #define trace_assign_type(var, ent)                                     \
 208         do {                                                            \
 209                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 210                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 211                 IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
 212                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 213                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 214                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 215                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 216                           TRACE_MMIO_RW);                               \
 217                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 218                           TRACE_MMIO_MAP);                              \
 219                 IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT);     \
 220                 __ftrace_bad_type();                                    \
 221         } while (0)
 222
 223 /* Return values for print_line callback */
 224 enum print_line_t {
 225         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 226         TRACE_TYPE_HANDLED      = 1,
 227         TRACE_TYPE_UNHANDLED    = 2     /* Relay to other output functions */
 228 };
 229
 230 /*
 231  * A specific tracer, represented by methods that operate on a trace array:
 232  */
 233 struct tracer {
 234         const char              *name;
 235         void                    (*init)(struct trace_array *tr);
 236         void                    (*reset)(struct trace_array *tr);
 237         void                    (*open)(struct trace_iterator *iter);
 238         void                    (*pipe_open)(struct trace_iterator *iter);
 239         void                    (*close)(struct trace_iterator *iter);
 240         void                    (*start)(struct trace_iterator *iter);
 241         void                    (*stop)(struct trace_iterator *iter);
 242         ssize_t                 (*read)(struct trace_iterator *iter,
 243                                         struct file *filp, char __user *ubuf,
 244                                         size_t cnt, loff_t *ppos);
 245         void                    (*ctrl_update)(struct trace_array *tr);
 246 #ifdef CONFIG_FTRACE_STARTUP_TEST
 247         int                     (*selftest)(struct tracer *trace,
 248                                             struct trace_array *tr);
 249 #endif
 250         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 251         struct tracer           *next;
 252         int                     print_max;
 253 };
 254
 255 struct trace_seq {
 256         unsigned char           buffer[PAGE_SIZE];
 257         unsigned int            len;
 258         unsigned int            readpos;
 259 };
 260
 261 /*
 262  * Trace iterator - used by printout routines who present trace
 263  * results to users and which routines might sleep, etc:
 264  */
 265 struct trace_iterator {
 266         struct trace_array      *tr;
 267         struct tracer           *trace;
 268         void                    *private;
 269         struct ring_buffer_iter *buffer_iter[NR_CPUS];
 270
 271         /* The below is zeroed out in pipe_read */
 272         struct trace_seq        seq;
 273         struct trace_entry      *ent;
 274         int                     cpu;
 275         u64                     ts;
 276
 277         unsigned long           iter_flags;
 278         loff_t                  pos;
 279         long                    idx;
 280 };
 281
 282 void trace_wake_up(void);
 283 void tracing_reset(struct trace_array *tr, int cpu);
 284 int tracing_open_generic(struct inode *inode, struct file *filp);
 285 struct dentry *tracing_init_dentry(void);
 286 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 287
 288 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 289                                                 struct trace_array_cpu *data);
 290 void tracing_generic_entry_update(struct trace_entry *entry,
 291                                   unsigned long flags,
 292                                   int pc);
 293
 294 void ftrace(struct trace_array *tr,
 295                             struct trace_array_cpu *data,
 296                             unsigned long ip,
 297                             unsigned long parent_ip,
 298                             unsigned long flags, int pc);
 299 void tracing_sched_switch_trace(struct trace_array *tr,
 300                                 struct trace_array_cpu *data,
 301                                 struct task_struct *prev,
 302                                 struct task_struct *next,
 303                                 unsigned long flags, int pc);
 304 void tracing_record_cmdline(struct task_struct *tsk);
 305
 306 void tracing_sched_wakeup_trace(struct trace_array *tr,
 307                                 struct trace_array_cpu *data,
 308                                 struct task_struct *wakee,
 309                                 struct task_struct *cur,
 310                                 unsigned long flags, int pc);
 311 void trace_special(struct trace_array *tr,
 312                    struct trace_array_cpu *data,
 313                    unsigned long arg1,
 314                    unsigned long arg2,
 315                    unsigned long arg3, int pc);
 316 void trace_function(struct trace_array *tr,
 317                     struct trace_array_cpu *data,
 318                     unsigned long ip,
 319                     unsigned long parent_ip,
 320                     unsigned long flags, int pc);
 321
 322 void tracing_start_cmdline_record(void);
 323 void tracing_stop_cmdline_record(void);
 324 int register_tracer(struct tracer *type);
 325 void unregister_tracer(struct tracer *type);
 326
 327 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 328
 329 extern unsigned long tracing_max_latency;
 330 extern unsigned long tracing_thresh;
 331
 332 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 333 void update_max_tr_single(struct trace_array *tr,
 334                           struct task_struct *tsk, int cpu);
 335
 336 extern cycle_t ftrace_now(int cpu);
 337
 338 #ifdef CONFIG_FTRACE
 339 void tracing_start_function_trace(void);
 340 void tracing_stop_function_trace(void);
 341 #else
 342 # define tracing_start_function_trace()         do { } while (0)
 343 # define tracing_stop_function_trace()          do { } while (0)
 344 #endif
 345
 346 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 347 typedef void
 348 (*tracer_switch_func_t)(void *private,
 349                         void *__rq,
 350                         struct task_struct *prev,
 351                         struct task_struct *next);
 352
 353 struct tracer_switch_ops {
 354         tracer_switch_func_t            func;
 355         void                            *private;
 356         struct tracer_switch_ops        *next;
 357 };
 358
 359 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 360
 361 #ifdef CONFIG_DYNAMIC_FTRACE
 362 extern unsigned long ftrace_update_tot_cnt;
 363 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 364 extern int DYN_FTRACE_TEST_NAME(void);
 365 #endif
 366
 367 #ifdef CONFIG_FTRACE_STARTUP_TEST
 368 extern int trace_selftest_startup_function(struct tracer *trace,
 369                                            struct trace_array *tr);
 370 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 371                                           struct trace_array *tr);
 372 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 373                                              struct trace_array *tr);
 374 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 375                                                  struct trace_array *tr);
 376 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 377                                          struct trace_array *tr);
 378 extern int trace_selftest_startup_nop(struct tracer *trace,
 379                                          struct trace_array *tr);
 380 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 381                                                struct trace_array *tr);
 382 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 383                                                struct trace_array *tr);
 384 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 385
 386 extern void *head_page(struct trace_array_cpu *data);
 387 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
 388 extern void trace_seq_print_cont(struct trace_seq *s,
 389                                  struct trace_iterator *iter);
 390 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
 391                                  size_t cnt);
 392 extern long ns2usecs(cycle_t nsec);
 393 extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 394
 395 extern unsigned long trace_flags;
 396
 397 /*
 398  * trace_iterator_flags is an enumeration that defines bit
 399  * positions into trace_flags that controls the output.
 400  *
 401  * NOTE: These bits must match the trace_options array in
 402  *       trace.c.
 403  */
 404 enum trace_iterator_flags {
 405         TRACE_ITER_PRINT_PARENT         = 0x01,
 406         TRACE_ITER_SYM_OFFSET           = 0x02,
 407         TRACE_ITER_SYM_ADDR             = 0x04,
 408         TRACE_ITER_VERBOSE              = 0x08,
 409         TRACE_ITER_RAW                  = 0x10,
 410         TRACE_ITER_HEX                  = 0x20,
 411         TRACE_ITER_BIN                  = 0x40,
 412         TRACE_ITER_BLOCK                = 0x80,
 413         TRACE_ITER_STACKTRACE           = 0x100,
 414         TRACE_ITER_SCHED_TREE           = 0x200,
 415         TRACE_ITER_PRINTK               = 0x400,
 416 };
 417
 418 extern struct tracer nop_trace;
 419
 420 #endif /* _LINUX_KERNEL_TRACE_H */