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 const char *ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
  24                                      const struct trace_print_flags *symbol_array);
  25
  26 /*
  27  * The trace entry - the most basic unit of tracing. This is what
  28  * is printed in the end as a single line in the trace output, such as:
  29  *
  30  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  31  */
  32 struct trace_entry {
  33         unsigned short          type;
  34         unsigned char           flags;
  35         unsigned char           preempt_count;
  36         int                     pid;
  37         int                     tgid;
  38 };
  39
  40 #define FTRACE_MAX_EVENT                                                \
  41         ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  42
  43 /*
  44  * Trace iterator - used by printout routines who present trace
  45  * results to users and which routines might sleep, etc:
  46  */
  47 struct trace_iterator {
  48         struct trace_array      *tr;
  49         struct tracer           *trace;
  50         void                    *private;
  51         int                     cpu_file;
  52         struct mutex            mutex;
  53         struct ring_buffer_iter *buffer_iter[NR_CPUS];
  54         unsigned long           iter_flags;
  55
  56         /* The below is zeroed out in pipe_read */
  57         struct trace_seq        seq;
  58         struct trace_entry      *ent;
  59         int                     cpu;
  60         u64                     ts;
  61
  62         loff_t                  pos;
  63         long                    idx;
  64
  65         cpumask_var_t           started;
  66 };
  67
  68
  69 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
  70                                               int flags);
  71 struct trace_event {
  72         struct hlist_node       node;
  73         struct list_head        list;
  74         int                     type;
  75         trace_print_func        trace;
  76         trace_print_func        raw;
  77         trace_print_func        hex;
  78         trace_print_func        binary;
  79 };
  80
  81 extern int register_ftrace_event(struct trace_event *event);
  82 extern int unregister_ftrace_event(struct trace_event *event);
  83
  84 /* Return values for print_line callback */
  85 enum print_line_t {
  86         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
  87         TRACE_TYPE_HANDLED      = 1,
  88         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
  89         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
  90 };
  91
  92
  93 struct ring_buffer_event *
  94 trace_current_buffer_lock_reserve(int type, unsigned long len,
  95                                   unsigned long flags, int pc);
  96 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
  97                                         unsigned long flags, int pc);
  98 void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event,
  99                                         unsigned long flags, int pc);
 100 void trace_current_buffer_discard_commit(struct ring_buffer_event *event);
 101
 102 void tracing_record_cmdline(struct task_struct *tsk);
 103
 104 struct ftrace_event_call {
 105         struct list_head        list;
 106         char                    *name;
 107         char                    *system;
 108         struct dentry           *dir;
 109         struct trace_event      *event;
 110         int                     enabled;
 111         int                     (*regfunc)(void);
 112         void                    (*unregfunc)(void);
 113         int                     id;
 114         int                     (*raw_init)(void);
 115         int                     (*show_format)(struct trace_seq *s);
 116         int                     (*define_fields)(void);
 117         struct list_head        fields;
 118         int                     filter_active;
 119         void                    *filter;
 120         void                    *mod;
 121
 122 #ifdef CONFIG_EVENT_PROFILE
 123         atomic_t        profile_count;
 124         int             (*profile_enable)(struct ftrace_event_call *);
 125         void            (*profile_disable)(struct ftrace_event_call *);
 126 #endif
 127 };
 128
 129 #define MAX_FILTER_PRED         32
 130 #define MAX_FILTER_STR_VAL      128
 131
 132 extern int init_preds(struct ftrace_event_call *call);
 133 extern void destroy_preds(struct ftrace_event_call *call);
 134 extern int filter_match_preds(struct ftrace_event_call *call, void *rec);
 135 extern int filter_current_check_discard(struct ftrace_event_call *call,
 136                                         void *rec,
 137                                         struct ring_buffer_event *event);
 138
 139 extern int trace_define_field(struct ftrace_event_call *call, char *type,
 140                               char *name, int offset, int size, int is_signed);
 141
 142 #define is_signed_type(type)    (((type)(-1)) < 0)
 143
 144 int trace_set_clr_event(const char *system, const char *event, int set);
 145
 146 /*
 147  * The double __builtin_constant_p is because gcc will give us an error
 148  * if we try to allocate the static variable to fmt if it is not a
 149  * constant. Even with the outer if statement optimizing out.
 150  */
 151 #define event_trace_printk(ip, fmt, args...)                            \
 152 do {                                                                    \
 153         __trace_printk_check_format(fmt, ##args);                       \
 154         tracing_record_cmdline(current);                                \
 155         if (__builtin_constant_p(fmt)) {                                \
 156                 static const char *trace_printk_fmt                     \
 157                   __attribute__((section("__trace_printk_fmt"))) =      \
 158                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 159                                                                         \
 160                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 161         } else                                                          \
 162                 __trace_printk(ip, fmt, ##args);                        \
 163 } while (0)
 164
 165 #define __common_field(type, item, is_signed)                           \
 166         ret = trace_define_field(event_call, #type, "common_" #item,    \
 167                                  offsetof(typeof(field.ent), item),     \
 168                                  sizeof(field.ent.item), is_signed);    \
 169         if (ret)                                                        \
 170                 return ret;
 171
 172 #endif /* _LINUX_FTRACE_EVENT_H */