include/linux/ftrace_event.h

   1 #ifndef _LINUX_FTRACE_EVENT_H
   2 #define _LINUX_FTRACE_EVENT_H
   3
   4 #include <linux/ring_buffer.h>
   5 #include <linux/trace_seq.h>
   6 #include <linux/percpu.h>
   7 #include <linux/hardirq.h>
   8 #include <linux/perf_event.h>
   9
  10 struct trace_array;
  11 struct tracer;
  12 struct dentry;
  13
  14 DECLARE_PER_CPU(struct trace_seq, ftrace_event_seq);
  15
  16 struct trace_print_flags {
  17         unsigned long           mask;
  18         const char              *name;
  19 };
  20
  21 const char *ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
  22                                    unsigned long flags,
  23                                    const struct trace_print_flags *flag_array);
  24
  25 const char *ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
  26                                      const struct trace_print_flags *symbol_array);
  27
  28 /*
  29  * The trace entry - the most basic unit of tracing. This is what
  30  * is printed in the end as a single line in the trace output, such as:
  31  *
  32  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  33  */
  34 struct trace_entry {
  35         unsigned short          type;
  36         unsigned char           flags;
  37         unsigned char           preempt_count;
  38         int                     pid;
  39         int                     lock_depth;
  40 };
  41
  42 #define FTRACE_MAX_EVENT                                                \
  43         ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  44
  45 /*
  46  * Trace iterator - used by printout routines who present trace
  47  * results to users and which routines might sleep, etc:
  48  */
  49 struct trace_iterator {
  50         struct trace_array      *tr;
  51         struct tracer           *trace;
  52         void                    *private;
  53         int                     cpu_file;
  54         struct mutex            mutex;
  55         struct ring_buffer_iter *buffer_iter[NR_CPUS];
  56         unsigned long           iter_flags;
  57
  58         /* The below is zeroed out in pipe_read */
  59         struct trace_seq        seq;
  60         struct trace_entry      *ent;
  61         unsigned long           lost_events;
  62         int                     leftover;
  63         int                     cpu;
  64         u64                     ts;
  65
  66         loff_t                  pos;
  67         long                    idx;
  68
  69         cpumask_var_t           started;
  70 };
  71
  72
  73 struct trace_event;
  74
  75 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
  76                                       int flags, struct trace_event *event);
  77
  78 struct trace_event_functions {
  79         trace_print_func        trace;
  80         trace_print_func        raw;
  81         trace_print_func        hex;
  82         trace_print_func        binary;
  83 };
  84
  85 struct trace_event {
  86         struct hlist_node               node;
  87         struct list_head                list;
  88         int                             type;
  89         struct trace_event_functions    *funcs;
  90 };
  91
  92 extern int register_ftrace_event(struct trace_event *event);
  93 extern int unregister_ftrace_event(struct trace_event *event);
  94
  95 /* Return values for print_line callback */
  96 enum print_line_t {
  97         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
  98         TRACE_TYPE_HANDLED      = 1,
  99         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 100         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 101 };
 102
 103 void tracing_generic_entry_update(struct trace_entry *entry,
 104                                   unsigned long flags,
 105                                   int pc);
 106 struct ring_buffer_event *
 107 trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
 108                                   int type, unsigned long len,
 109                                   unsigned long flags, int pc);
 110 void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
 111                                         struct ring_buffer_event *event,
 112                                         unsigned long flags, int pc);
 113 void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
 114                                        struct ring_buffer_event *event,
 115                                         unsigned long flags, int pc);
 116 void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 117                                          struct ring_buffer_event *event);
 118
 119 void tracing_record_cmdline(struct task_struct *tsk);
 120
 121 struct event_filter;
 122
 123 enum trace_reg {
 124         TRACE_REG_REGISTER,
 125         TRACE_REG_UNREGISTER,
 126         TRACE_REG_PERF_REGISTER,
 127         TRACE_REG_PERF_UNREGISTER,
 128 };
 129
 130 struct ftrace_event_call;
 131
 132 struct ftrace_event_class {
 133         char                    *system;
 134         void                    *probe;
 135 #ifdef CONFIG_PERF_EVENTS
 136         void                    *perf_probe;
 137 #endif
 138         int                     (*reg)(struct ftrace_event_call *event,
 139                                        enum trace_reg type);
 140         int                     (*define_fields)(struct ftrace_event_call *);
 141         struct list_head        *(*get_fields)(struct ftrace_event_call *);
 142         struct list_head        fields;
 143         int                     (*raw_init)(struct ftrace_event_call *);
 144 };
 145
 146 enum {
 147         TRACE_EVENT_FL_ENABLED_BIT,
 148         TRACE_EVENT_FL_FILTERED_BIT,
 149 };
 150
 151 enum {
 152         TRACE_EVENT_FL_ENABLED  = (1 << TRACE_EVENT_FL_ENABLED_BIT),
 153         TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT),
 154 };
 155
 156 struct ftrace_event_call {
 157         struct list_head        list;
 158         struct ftrace_event_class *class;
 159         char                    *name;
 160         struct dentry           *dir;
 161         struct trace_event      event;
 162         const char              *print_fmt;
 163         struct event_filter     *filter;
 164         void                    *mod;
 165         void                    *data;
 166
 167         /*
 168          * 32 bit flags:
 169          *   bit 1:             enabled
 170          *   bit 2:             filter_active
 171          *
 172          * Changes to flags must hold the event_mutex.
 173          *
 174          * Note: Reads of flags do not hold the event_mutex since
 175          * they occur in critical sections. But the way flags
 176          * is currently used, these changes do no affect the code
 177          * except that when a change is made, it may have a slight
 178          * delay in propagating the changes to other CPUs due to
 179          * caching and such.
 180          */
 181         unsigned int            flags;
 182
 183 #ifdef CONFIG_PERF_EVENTS
 184         int                     perf_refcount;
 185         struct hlist_head       *perf_events;
 186 #endif
 187 };
 188
 189 #define PERF_MAX_TRACE_SIZE     2048
 190
 191 #define MAX_FILTER_PRED         32
 192 #define MAX_FILTER_STR_VAL      256     /* Should handle KSYM_SYMBOL_LEN */
 193
 194 extern void destroy_preds(struct ftrace_event_call *call);
 195 extern int filter_match_preds(struct event_filter *filter, void *rec);
 196 extern int filter_current_check_discard(struct ring_buffer *buffer,
 197                                         struct ftrace_event_call *call,
 198                                         void *rec,
 199                                         struct ring_buffer_event *event);
 200
 201 enum {
 202         FILTER_OTHER = 0,
 203         FILTER_STATIC_STRING,
 204         FILTER_DYN_STRING,
 205         FILTER_PTR_STRING,
 206 };
 207
 208 extern int trace_event_raw_init(struct ftrace_event_call *call);
 209 extern int trace_define_field(struct ftrace_event_call *call, const char *type,
 210                               const char *name, int offset, int size,
 211                               int is_signed, int filter_type);
 212 extern int trace_add_event_call(struct ftrace_event_call *call);
 213 extern void trace_remove_event_call(struct ftrace_event_call *call);
 214
 215 #define is_signed_type(type)    (((type)(-1)) < 0)
 216
 217 int trace_set_clr_event(const char *system, const char *event, int set);
 218
 219 /*
 220  * The double __builtin_constant_p is because gcc will give us an error
 221  * if we try to allocate the static variable to fmt if it is not a
 222  * constant. Even with the outer if statement optimizing out.
 223  */
 224 #define event_trace_printk(ip, fmt, args...)                            \
 225 do {                                                                    \
 226         __trace_printk_check_format(fmt, ##args);                       \
 227         tracing_record_cmdline(current);                                \
 228         if (__builtin_constant_p(fmt)) {                                \
 229                 static const char *trace_printk_fmt                     \
 230                   __attribute__((section("__trace_printk_fmt"))) =      \
 231                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 232                                                                         \
 233                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 234         } else                                                          \
 235                 __trace_printk(ip, fmt, ##args);                        \
 236 } while (0)
 237
 238 #ifdef CONFIG_PERF_EVENTS
 239 struct perf_event;
 240
 241 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 242
 243 extern int  perf_trace_init(struct perf_event *event);
 244 extern void perf_trace_destroy(struct perf_event *event);
 245 extern int  perf_trace_enable(struct perf_event *event);
 246 extern void perf_trace_disable(struct perf_event *event);
 247 extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 248                                      char *filter_str);
 249 extern void ftrace_profile_free_filter(struct perf_event *event);
 250 extern void *perf_trace_buf_prepare(int size, unsigned short type,
 251                                     struct pt_regs *regs, int *rctxp);
 252
 253 static inline void
 254 perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
 255                        u64 count, struct pt_regs *regs, void *head)
 256 {
 257         perf_tp_event(addr, count, raw_data, size, regs, head);
 258         perf_swevent_put_recursion_context(rctx);
 259 }
 260 #endif
 261
 262 #endif /* _LINUX_FTRACE_EVENT_H */