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
   9 enum trace_type {
  10         __TRACE_FIRST_TYPE = 0,
  11
  12         TRACE_FN,
  13         TRACE_CTX,
  14         TRACE_WAKE,
  15         TRACE_STACK,
  16         TRACE_SPECIAL,
  17
  18         __TRACE_LAST_TYPE
  19 };
  20
  21 /*
  22  * Function trace entry - function address and parent function addres:
  23  */
  24 struct ftrace_entry {
  25         unsigned long           ip;
  26         unsigned long           parent_ip;
  27 };
  28
  29 /*
  30  * Context switch trace entry - which task (and prio) we switched from/to:
  31  */
  32 struct ctx_switch_entry {
  33         unsigned int            prev_pid;
  34         unsigned char           prev_prio;
  35         unsigned char           prev_state;
  36         unsigned int            next_pid;
  37         unsigned char           next_prio;
  38         unsigned char           next_state;
  39 };
  40
  41 /*
  42  * Special (free-form) trace entry:
  43  */
  44 struct special_entry {
  45         unsigned long           arg1;
  46         unsigned long           arg2;
  47         unsigned long           arg3;
  48 };
  49
  50 /*
  51  * Stack-trace entry:
  52  */
  53
  54 #define FTRACE_STACK_ENTRIES    5
  55
  56 struct stack_entry {
  57         unsigned long           caller[FTRACE_STACK_ENTRIES];
  58 };
  59
  60 /*
  61  * The trace entry - the most basic unit of tracing. This is what
  62  * is printed in the end as a single line in the trace output, such as:
  63  *
  64  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  65  */
  66 struct trace_entry {
  67         char                    type;
  68         char                    cpu;
  69         char                    flags;
  70         char                    preempt_count;
  71         int                     pid;
  72         cycle_t                 t;
  73         union {
  74                 struct ftrace_entry             fn;
  75                 struct ctx_switch_entry         ctx;
  76                 struct special_entry            special;
  77                 struct stack_entry              stack;
  78         };
  79 };
  80
  81 #define TRACE_ENTRY_SIZE        sizeof(struct trace_entry)
  82
  83 /*
  84  * The CPU trace array - it consists of thousands of trace entries
  85  * plus some other descriptor data: (for example which task started
  86  * the trace, etc.)
  87  */
  88 struct trace_array_cpu {
  89         struct list_head        trace_pages;
  90         atomic_t                disabled;
  91         raw_spinlock_t          lock;
  92         struct lock_class_key   lock_key;
  93
  94         /* these fields get copied into max-trace: */
  95         unsigned                trace_head_idx;
  96         unsigned                trace_tail_idx;
  97         void                    *trace_head; /* producer */
  98         void                    *trace_tail; /* consumer */
  99         unsigned long           trace_idx;
 100         unsigned long           overrun;
 101         unsigned long           saved_latency;
 102         unsigned long           critical_start;
 103         unsigned long           critical_end;
 104         unsigned long           critical_sequence;
 105         unsigned long           nice;
 106         unsigned long           policy;
 107         unsigned long           rt_priority;
 108         cycle_t                 preempt_timestamp;
 109         pid_t                   pid;
 110         uid_t                   uid;
 111         char                    comm[TASK_COMM_LEN];
 112 };
 113
 114 struct trace_iterator;
 115
 116 /*
 117  * The trace array - an array of per-CPU trace arrays. This is the
 118  * highest level data structure that individual tracers deal with.
 119  * They have on/off state as well:
 120  */
 121 struct trace_array {
 122         unsigned long           entries;
 123         long                    ctrl;
 124         int                     cpu;
 125         cycle_t                 time_start;
 126         struct task_struct      *waiter;
 127         struct trace_array_cpu  *data[NR_CPUS];
 128 };
 129
 130 /*
 131  * A specific tracer, represented by methods that operate on a trace array:
 132  */
 133 struct tracer {
 134         const char              *name;
 135         void                    (*init)(struct trace_array *tr);
 136         void                    (*reset)(struct trace_array *tr);
 137         void                    (*open)(struct trace_iterator *iter);
 138         void                    (*pipe_open)(struct trace_iterator *iter);
 139         void                    (*close)(struct trace_iterator *iter);
 140         void                    (*start)(struct trace_iterator *iter);
 141         void                    (*stop)(struct trace_iterator *iter);
 142         ssize_t                 (*read)(struct trace_iterator *iter,
 143                                         struct file *filp, char __user *ubuf,
 144                                         size_t cnt, loff_t *ppos);
 145         void                    (*ctrl_update)(struct trace_array *tr);
 146 #ifdef CONFIG_FTRACE_STARTUP_TEST
 147         int                     (*selftest)(struct tracer *trace,
 148                                             struct trace_array *tr);
 149 #endif
 150         int                     (*print_line)(struct trace_iterator *iter);
 151         struct tracer           *next;
 152         int                     print_max;
 153 };
 154
 155 struct trace_seq {
 156         unsigned char           buffer[PAGE_SIZE];
 157         unsigned int            len;
 158         unsigned int            readpos;
 159 };
 160
 161 /*
 162  * Trace iterator - used by printout routines who present trace
 163  * results to users and which routines might sleep, etc:
 164  */
 165 struct trace_iterator {
 166         struct trace_array      *tr;
 167         struct tracer           *trace;
 168         void                    *private;
 169         long                    last_overrun[NR_CPUS];
 170         long                    overrun[NR_CPUS];
 171
 172         /* The below is zeroed out in pipe_read */
 173         struct trace_seq        seq;
 174         struct trace_entry      *ent;
 175         int                     cpu;
 176
 177         struct trace_entry      *prev_ent;
 178         int                     prev_cpu;
 179
 180         unsigned long           iter_flags;
 181         loff_t                  pos;
 182         unsigned long           next_idx[NR_CPUS];
 183         struct list_head        *next_page[NR_CPUS];
 184         unsigned                next_page_idx[NR_CPUS];
 185         long                    idx;
 186 };
 187
 188 void tracing_reset(struct trace_array_cpu *data);
 189 int tracing_open_generic(struct inode *inode, struct file *filp);
 190 struct dentry *tracing_init_dentry(void);
 191 void ftrace(struct trace_array *tr,
 192                             struct trace_array_cpu *data,
 193                             unsigned long ip,
 194                             unsigned long parent_ip,
 195                             unsigned long flags);
 196 void tracing_sched_switch_trace(struct trace_array *tr,
 197                                 struct trace_array_cpu *data,
 198                                 struct task_struct *prev,
 199                                 struct task_struct *next,
 200                                 unsigned long flags);
 201 void tracing_record_cmdline(struct task_struct *tsk);
 202
 203 void tracing_sched_wakeup_trace(struct trace_array *tr,
 204                                 struct trace_array_cpu *data,
 205                                 struct task_struct *wakee,
 206                                 struct task_struct *cur,
 207                                 unsigned long flags);
 208 void trace_special(struct trace_array *tr,
 209                    struct trace_array_cpu *data,
 210                    unsigned long arg1,
 211                    unsigned long arg2,
 212                    unsigned long arg3);
 213 void trace_function(struct trace_array *tr,
 214                     struct trace_array_cpu *data,
 215                     unsigned long ip,
 216                     unsigned long parent_ip,
 217                     unsigned long flags);
 218
 219 void tracing_start_function_trace(void);
 220 void tracing_stop_function_trace(void);
 221 int register_tracer(struct tracer *type);
 222 void unregister_tracer(struct tracer *type);
 223
 224 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 225
 226 extern unsigned long tracing_max_latency;
 227 extern unsigned long tracing_thresh;
 228
 229 extern atomic_t trace_record_cmdline_enabled;
 230
 231 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 232 void update_max_tr_single(struct trace_array *tr,
 233                           struct task_struct *tsk, int cpu);
 234
 235 extern cycle_t ftrace_now(int cpu);
 236
 237 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 238 typedef void
 239 (*tracer_switch_func_t)(void *private,
 240                         void *__rq,
 241                         struct task_struct *prev,
 242                         struct task_struct *next);
 243
 244 struct tracer_switch_ops {
 245         tracer_switch_func_t            func;
 246         void                            *private;
 247         struct tracer_switch_ops        *next;
 248 };
 249
 250 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 251
 252 #ifdef CONFIG_DYNAMIC_FTRACE
 253 extern unsigned long ftrace_update_tot_cnt;
 254 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 255 extern int DYN_FTRACE_TEST_NAME(void);
 256 #endif
 257
 258 #ifdef CONFIG_FTRACE_STARTUP_TEST
 259 #ifdef CONFIG_FTRACE
 260 extern int trace_selftest_startup_function(struct tracer *trace,
 261                                            struct trace_array *tr);
 262 #endif
 263 #ifdef CONFIG_IRQSOFF_TRACER
 264 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 265                                           struct trace_array *tr);
 266 #endif
 267 #ifdef CONFIG_PREEMPT_TRACER
 268 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 269                                              struct trace_array *tr);
 270 #endif
 271 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 272 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 273                                                  struct trace_array *tr);
 274 #endif
 275 #ifdef CONFIG_SCHED_TRACER
 276 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 277                                          struct trace_array *tr);
 278 #endif
 279 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 280 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 281                                                struct trace_array *tr);
 282 #endif
 283 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 284
 285 extern void *head_page(struct trace_array_cpu *data);
 286 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
 287 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
 288                                  size_t cnt);
 289 extern long ns2usecs(cycle_t nsec);
 290
 291 extern unsigned long trace_flags;
 292
 293 /*
 294  * trace_iterator_flags is an enumeration that defines bit
 295  * positions into trace_flags that controls the output.
 296  *
 297  * NOTE: These bits must match the trace_options array in
 298  *       trace.c.
 299  */
 300 enum trace_iterator_flags {
 301         TRACE_ITER_PRINT_PARENT         = 0x01,
 302         TRACE_ITER_SYM_OFFSET           = 0x02,
 303         TRACE_ITER_SYM_ADDR             = 0x04,
 304         TRACE_ITER_VERBOSE              = 0x08,
 305         TRACE_ITER_RAW                  = 0x10,
 306         TRACE_ITER_HEX                  = 0x20,
 307         TRACE_ITER_BIN                  = 0x40,
 308         TRACE_ITER_BLOCK                = 0x80,
 309         TRACE_ITER_STACKTRACE           = 0x100,
 310         TRACE_ITER_SCHED_TREE           = 0x200,
 311 };
 312
 313 #endif /* _LINUX_KERNEL_TRACE_H */