include/linux/ftrace_event.h

   1 #ifndef _LINUX_FTRACE_EVENT_H
   2 #define _LINUX_FTRACE_EVENT_H
   3
   4 #include <linux/trace_seq.h>
   5 #include <linux/ring_buffer.h>
   6 #include <linux/percpu.h>
   7
   8 struct trace_array;
   9 struct tracer;
  10 struct dentry;
  11
  12 DECLARE_PER_CPU(struct trace_seq, ftrace_event_seq);
  13
  14 struct trace_print_flags {
  15         unsigned long           mask;
  16         const char              *name;
  17 };
  18
  19 const char *ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
  20                                    unsigned long flags,
  21                                    const struct trace_print_flags *flag_array);
  22
  23 /*
  24  * The trace entry - the most basic unit of tracing. This is what
  25  * is printed in the end as a single line in the trace output, such as:
  26  *
  27  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  28  */
  29 struct trace_entry {
  30         unsigned short          type;
  31         unsigned char           flags;
  32         unsigned char           preempt_count;
  33         int                     pid;
  34         int                     tgid;
  35 };
  36
  37 #define FTRACE_MAX_EVENT                                                \
  38         ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  39
  40 /*
  41  * Trace iterator - used by printout routines who present trace
  42  * results to users and which routines might sleep, etc:
  43  */
  44 struct trace_iterator {
  45         struct trace_array      *tr;
  46         struct tracer           *trace;
  47         void                    *private;
  48         int                     cpu_file;
  49         struct mutex            mutex;
  50         struct ring_buffer_iter *buffer_iter[NR_CPUS];
  51
  52         /* The below is zeroed out in pipe_read */
  53         struct trace_seq        seq;
  54         struct trace_entry      *ent;
  55         int                     cpu;
  56         u64                     ts;
  57
  58         unsigned long           iter_flags;
  59         loff_t                  pos;
  60         long                    idx;
  61
  62         cpumask_var_t           started;
  63 };
  64
  65
  66 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
  67                                               int flags);
  68 struct trace_event {
  69         struct hlist_node       node;
  70         struct list_head        list;
  71         int                     type;
  72         trace_print_func        trace;
  73         trace_print_func        raw;
  74         trace_print_func        hex;
  75         trace_print_func        binary;
  76 };
  77
  78 extern int register_ftrace_event(struct trace_event *event);
  79 extern int unregister_ftrace_event(struct trace_event *event);
  80
  81 /* Return values for print_line callback */
  82 enum print_line_t {
  83         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
  84         TRACE_TYPE_HANDLED      = 1,
  85         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
  86         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
  87 };
  88
  89
  90 struct ring_buffer_event *
  91 trace_current_buffer_lock_reserve(int type, unsigned long len,
  92                                   unsigned long flags, int pc);
  93 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
  94                                         unsigned long flags, int pc);
  95 void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event,
  96                                         unsigned long flags, int pc);
  97 void trace_current_buffer_discard_commit(struct ring_buffer_event *event);
  98
  99 void tracing_record_cmdline(struct task_struct *tsk);
 100
 101 struct ftrace_event_call {
 102         struct list_head        list;
 103         char                    *name;
 104         char                    *system;
 105         struct dentry           *dir;
 106         struct trace_event      *event;
 107         int                     enabled;
 108         int                     (*regfunc)(void);
 109         void                    (*unregfunc)(void);
 110         int                     id;
 111         int                     (*raw_init)(void);
 112         int                     (*show_format)(struct trace_seq *s);
 113         int                     (*define_fields)(void);
 114         struct list_head        fields;
 115         int                     filter_active;
 116         void                    *filter;
 117         void                    *mod;
 118
 119 #ifdef CONFIG_EVENT_PROFILE
 120         atomic_t        profile_count;
 121         int             (*profile_enable)(struct ftrace_event_call *);
 122         void            (*profile_disable)(struct ftrace_event_call *);
 123 #endif
 124 };
 125
 126 #define MAX_FILTER_PRED         32
 127 #define MAX_FILTER_STR_VAL      128
 128
 129 extern int init_preds(struct ftrace_event_call *call);
 130 extern void destroy_preds(struct ftrace_event_call *call);
 131 extern int filter_match_preds(struct ftrace_event_call *call, void *rec);
 132 extern int filter_current_check_discard(struct ftrace_event_call *call,
 133                                         void *rec,
 134                                         struct ring_buffer_event *event);
 135
 136 extern int trace_define_field(struct ftrace_event_call *call, char *type,
 137                               char *name, int offset, int size, int is_signed);
 138
 139 #define is_signed_type(type)    (((type)(-1)) < 0)
 140
 141 int trace_set_clr_event(const char *system, const char *event, int set);
 142
 143 /*
 144  * The double __builtin_constant_p is because gcc will give us an error
 145  * if we try to allocate the static variable to fmt if it is not a
 146  * constant. Even with the outer if statement optimizing out.
 147  */
 148 #define event_trace_printk(ip, fmt, args...)                            \
 149 do {                                                                    \
 150         __trace_printk_check_format(fmt, ##args);                       \
 151         tracing_record_cmdline(current);                                \
 152         if (__builtin_constant_p(fmt)) {                                \
 153                 static const char *trace_printk_fmt                     \
 154                   __attribute__((section("__trace_printk_fmt"))) =      \
 155                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 156                                                                         \
 157                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 158         } else                                                          \
 159                 __trace_printk(ip, fmt, ##args);                        \
 160 } while (0)
 161
 162 #define __common_field(type, item, is_signed)                           \
 163         ret = trace_define_field(event_call, #type, "common_" #item,    \
 164                                  offsetof(typeof(field.ent), item),     \
 165                                  sizeof(field.ent.item), is_signed);    \
 166         if (ret)                                                        \
 167                 return ret;
 168
 169 #endif /* _LINUX_FTRACE_EVENT_H */