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/mmiotrace.h>
   9 #include <linux/ftrace.h>
  10
  11 enum trace_type {
  12         __TRACE_FIRST_TYPE = 0,
  13
  14         TRACE_FN,
  15         TRACE_CTX,
  16         TRACE_WAKE,
  17         TRACE_CONT,
  18         TRACE_STACK,
  19         TRACE_PRINT,
  20         TRACE_SPECIAL,
  21         TRACE_MMIO_RW,
  22         TRACE_MMIO_MAP,
  23         TRACE_BOOT,
  24
  25         __TRACE_LAST_TYPE
  26 };
  27
  28 /*
  29  * Function trace entry - function address and parent function addres:
  30  */
  31 struct ftrace_entry {
  32         unsigned long           ip;
  33         unsigned long           parent_ip;
  34 };
  35 extern struct tracer boot_tracer;
  36
  37 /*
  38  * Context switch trace entry - which task (and prio) we switched from/to:
  39  */
  40 struct ctx_switch_entry {
  41         unsigned int            prev_pid;
  42         unsigned char           prev_prio;
  43         unsigned char           prev_state;
  44         unsigned int            next_pid;
  45         unsigned char           next_prio;
  46         unsigned char           next_state;
  47         unsigned int            next_cpu;
  48 };
  49
  50 /*
  51  * Special (free-form) trace entry:
  52  */
  53 struct special_entry {
  54         unsigned long           arg1;
  55         unsigned long           arg2;
  56         unsigned long           arg3;
  57 };
  58
  59 /*
  60  * Stack-trace entry:
  61  */
  62
  63 #define FTRACE_STACK_ENTRIES    8
  64
  65 struct stack_entry {
  66         unsigned long           caller[FTRACE_STACK_ENTRIES];
  67 };
  68
  69 /*
  70  * ftrace_printk entry:
  71  */
  72 struct print_entry {
  73         unsigned long           ip;
  74         char                    buf[];
  75 };
  76
  77 /*
  78  * trace_flag_type is an enumeration that holds different
  79  * states when a trace occurs. These are:
  80  *  IRQS_OFF    - interrupts were disabled
  81  *  NEED_RESCED - reschedule is requested
  82  *  HARDIRQ     - inside an interrupt handler
  83  *  SOFTIRQ     - inside a softirq handler
  84  *  CONT        - multiple entries hold the trace item
  85  */
  86 enum trace_flag_type {
  87         TRACE_FLAG_IRQS_OFF             = 0x01,
  88         TRACE_FLAG_NEED_RESCHED         = 0x02,
  89         TRACE_FLAG_HARDIRQ              = 0x04,
  90         TRACE_FLAG_SOFTIRQ              = 0x08,
  91         TRACE_FLAG_CONT                 = 0x10,
  92 };
  93
  94 /*
  95  * The trace field - the most basic unit of tracing. This is what
  96  * is printed in the end as a single line in the trace output, such as:
  97  *
  98  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  99  */
 100 struct trace_field {
 101         char                    cpu;
 102         char                    flags;
 103         char                    preempt_count;
 104         int                     pid;
 105         cycle_t                 t;
 106         union {
 107                 struct ftrace_entry             fn;
 108                 struct ctx_switch_entry         ctx;
 109                 struct special_entry            special;
 110                 struct stack_entry              stack;
 111                 struct print_entry              print;
 112                 struct mmiotrace_rw             mmiorw;
 113                 struct mmiotrace_map            mmiomap;
 114                 struct boot_trace               initcall;
 115         };
 116 };
 117
 118 struct trace_field_cont {
 119         char                            buf[sizeof(struct trace_field)];
 120 };
 121
 122 struct trace_entry {
 123         char                            type;
 124         union {
 125                 struct trace_field      field;
 126                 struct trace_field_cont cont;
 127         };
 128 };
 129
 130 #define TRACE_ENTRY_SIZE        sizeof(struct trace_entry)
 131 #define TRACE_BUF_SIZE          1024
 132 #define TRACE_PRINT_BUF_SIZE \
 133         (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf))
 134 #define TRACE_CONT_BUF_SIZE     sizeof(struct trace_field)
 135
 136 /*
 137  * The CPU trace array - it consists of thousands of trace entries
 138  * plus some other descriptor data: (for example which task started
 139  * the trace, etc.)
 140  */
 141 struct trace_array_cpu {
 142         struct list_head        trace_pages;
 143         atomic_t                disabled;
 144         raw_spinlock_t          lock;
 145         struct lock_class_key   lock_key;
 146
 147         /* these fields get copied into max-trace: */
 148         unsigned                trace_head_idx;
 149         unsigned                trace_tail_idx;
 150         void                    *trace_head; /* producer */
 151         void                    *trace_tail; /* consumer */
 152         unsigned long           trace_idx;
 153         unsigned long           overrun;
 154         unsigned long           saved_latency;
 155         unsigned long           critical_start;
 156         unsigned long           critical_end;
 157         unsigned long           critical_sequence;
 158         unsigned long           nice;
 159         unsigned long           policy;
 160         unsigned long           rt_priority;
 161         cycle_t                 preempt_timestamp;
 162         pid_t                   pid;
 163         uid_t                   uid;
 164         char                    comm[TASK_COMM_LEN];
 165 };
 166
 167 struct trace_iterator;
 168
 169 /*
 170  * The trace array - an array of per-CPU trace arrays. This is the
 171  * highest level data structure that individual tracers deal with.
 172  * They have on/off state as well:
 173  */
 174 struct trace_array {
 175         unsigned long           entries;
 176         long                    ctrl;
 177         int                     cpu;
 178         cycle_t                 time_start;
 179         struct task_struct      *waiter;
 180         struct trace_array_cpu  *data[NR_CPUS];
 181 };
 182
 183 /*
 184  * A specific tracer, represented by methods that operate on a trace array:
 185  */
 186 struct tracer {
 187         const char              *name;
 188         void                    (*init)(struct trace_array *tr);
 189         void                    (*reset)(struct trace_array *tr);
 190         void                    (*open)(struct trace_iterator *iter);
 191         void                    (*pipe_open)(struct trace_iterator *iter);
 192         void                    (*close)(struct trace_iterator *iter);
 193         void                    (*start)(struct trace_iterator *iter);
 194         void                    (*stop)(struct trace_iterator *iter);
 195         ssize_t                 (*read)(struct trace_iterator *iter,
 196                                         struct file *filp, char __user *ubuf,
 197                                         size_t cnt, loff_t *ppos);
 198         void                    (*ctrl_update)(struct trace_array *tr);
 199 #ifdef CONFIG_FTRACE_STARTUP_TEST
 200         int                     (*selftest)(struct tracer *trace,
 201                                             struct trace_array *tr);
 202 #endif
 203         int                     (*print_line)(struct trace_iterator *iter);
 204         struct tracer           *next;
 205         int                     print_max;
 206 };
 207
 208 struct trace_seq {
 209         unsigned char           buffer[PAGE_SIZE];
 210         unsigned int            len;
 211         unsigned int            readpos;
 212 };
 213
 214 /*
 215  * Trace iterator - used by printout routines who present trace
 216  * results to users and which routines might sleep, etc:
 217  */
 218 struct trace_iterator {
 219         struct trace_array      *tr;
 220         struct tracer           *trace;
 221         void                    *private;
 222         long                    last_overrun[NR_CPUS];
 223         long                    overrun[NR_CPUS];
 224
 225         /* The below is zeroed out in pipe_read */
 226         struct trace_seq        seq;
 227         struct trace_entry      *ent;
 228         int                     cpu;
 229
 230         struct trace_entry      *prev_ent;
 231         int                     prev_cpu;
 232
 233         unsigned long           iter_flags;
 234         loff_t                  pos;
 235         unsigned long           next_idx[NR_CPUS];
 236         struct list_head        *next_page[NR_CPUS];
 237         unsigned                next_page_idx[NR_CPUS];
 238         long                    idx;
 239 };
 240
 241 void trace_wake_up(void);
 242 void tracing_reset(struct trace_array_cpu *data);
 243 int tracing_open_generic(struct inode *inode, struct file *filp);
 244 struct dentry *tracing_init_dentry(void);
 245 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 246
 247 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 248                                                 struct trace_array_cpu *data);
 249 void tracing_generic_entry_update(struct trace_entry *entry,
 250                                                 unsigned long flags);
 251
 252 void ftrace(struct trace_array *tr,
 253                             struct trace_array_cpu *data,
 254                             unsigned long ip,
 255                             unsigned long parent_ip,
 256                             unsigned long flags);
 257 void tracing_sched_switch_trace(struct trace_array *tr,
 258                                 struct trace_array_cpu *data,
 259                                 struct task_struct *prev,
 260                                 struct task_struct *next,
 261                                 unsigned long flags);
 262 void tracing_record_cmdline(struct task_struct *tsk);
 263
 264 void tracing_sched_wakeup_trace(struct trace_array *tr,
 265                                 struct trace_array_cpu *data,
 266                                 struct task_struct *wakee,
 267                                 struct task_struct *cur,
 268                                 unsigned long flags);
 269 void trace_special(struct trace_array *tr,
 270                    struct trace_array_cpu *data,
 271                    unsigned long arg1,
 272                    unsigned long arg2,
 273                    unsigned long arg3);
 274 void trace_function(struct trace_array *tr,
 275                     struct trace_array_cpu *data,
 276                     unsigned long ip,
 277                     unsigned long parent_ip,
 278                     unsigned long flags);
 279
 280 void tracing_start_cmdline_record(void);
 281 void tracing_stop_cmdline_record(void);
 282 int register_tracer(struct tracer *type);
 283 void unregister_tracer(struct tracer *type);
 284
 285 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 286
 287 extern unsigned long tracing_max_latency;
 288 extern unsigned long tracing_thresh;
 289
 290 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 291 void update_max_tr_single(struct trace_array *tr,
 292                           struct task_struct *tsk, int cpu);
 293
 294 extern cycle_t ftrace_now(int cpu);
 295
 296 #ifdef CONFIG_FTRACE
 297 void tracing_start_function_trace(void);
 298 void tracing_stop_function_trace(void);
 299 #else
 300 # define tracing_start_function_trace()         do { } while (0)
 301 # define tracing_stop_function_trace()          do { } while (0)
 302 #endif
 303
 304 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 305 typedef void
 306 (*tracer_switch_func_t)(void *private,
 307                         void *__rq,
 308                         struct task_struct *prev,
 309                         struct task_struct *next);
 310
 311 struct tracer_switch_ops {
 312         tracer_switch_func_t            func;
 313         void                            *private;
 314         struct tracer_switch_ops        *next;
 315 };
 316
 317 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 318
 319 #ifdef CONFIG_DYNAMIC_FTRACE
 320 extern unsigned long ftrace_update_tot_cnt;
 321 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 322 extern int DYN_FTRACE_TEST_NAME(void);
 323 #endif
 324
 325 #ifdef CONFIG_FTRACE_STARTUP_TEST
 326 extern int trace_selftest_startup_function(struct tracer *trace,
 327                                            struct trace_array *tr);
 328 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 329                                           struct trace_array *tr);
 330 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 331                                              struct trace_array *tr);
 332 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 333                                                  struct trace_array *tr);
 334 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 335                                          struct trace_array *tr);
 336 extern int trace_selftest_startup_nop(struct tracer *trace,
 337                                          struct trace_array *tr);
 338 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 339                                                struct trace_array *tr);
 340 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 341                                                struct trace_array *tr);
 342 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 343
 344 extern void *head_page(struct trace_array_cpu *data);
 345 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
 346 extern void trace_seq_print_cont(struct trace_seq *s,
 347                                  struct trace_iterator *iter);
 348 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
 349                                  size_t cnt);
 350 extern long ns2usecs(cycle_t nsec);
 351 extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 352
 353 extern unsigned long trace_flags;
 354
 355 /*
 356  * trace_iterator_flags is an enumeration that defines bit
 357  * positions into trace_flags that controls the output.
 358  *
 359  * NOTE: These bits must match the trace_options array in
 360  *       trace.c.
 361  */
 362 enum trace_iterator_flags {
 363         TRACE_ITER_PRINT_PARENT         = 0x01,
 364         TRACE_ITER_SYM_OFFSET           = 0x02,
 365         TRACE_ITER_SYM_ADDR             = 0x04,
 366         TRACE_ITER_VERBOSE              = 0x08,
 367         TRACE_ITER_RAW                  = 0x10,
 368         TRACE_ITER_HEX                  = 0x20,
 369         TRACE_ITER_BIN                  = 0x40,
 370         TRACE_ITER_BLOCK                = 0x80,
 371         TRACE_ITER_STACKTRACE           = 0x100,
 372         TRACE_ITER_SCHED_TREE           = 0x200,
 373         TRACE_ITER_PRINTK               = 0x400,
 374 };
 375
 376 extern struct tracer nop_trace;
 377
 378 #endif /* _LINUX_KERNEL_TRACE_H */