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 const char *ftrace_print_hex_seq(struct trace_seq *p,
  29                                  const unsigned char *buf, int len);
  30
  31 /*
  32  * The trace entry - the most basic unit of tracing. This is what
  33  * is printed in the end as a single line in the trace output, such as:
  34  *
  35  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  36  */
  37 struct trace_entry {
  38         unsigned short          type;
  39         unsigned char           flags;
  40         unsigned char           preempt_count;
  41         int                     pid;
  42         int                     lock_depth;
  43 };
  44
  45 #define FTRACE_MAX_EVENT                                                \
  46         ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  47
  48 /*
  49  * Trace iterator - used by printout routines who present trace
  50  * results to users and which routines might sleep, etc:
  51  */
  52 struct trace_iterator {
  53         struct trace_array      *tr;
  54         struct tracer           *trace;
  55         void                    *private;
  56         int                     cpu_file;
  57         struct mutex            mutex;
  58         struct ring_buffer_iter *buffer_iter[NR_CPUS];
  59         unsigned long           iter_flags;
  60
  61         /* The below is zeroed out in pipe_read */
  62         struct trace_seq        seq;
  63         struct trace_entry      *ent;
  64         unsigned long           lost_events;
  65         int                     leftover;
  66         int                     cpu;
  67         u64                     ts;
  68
  69         loff_t                  pos;
  70         long                    idx;
  71
  72         cpumask_var_t           started;
  73 };
  74
  75
  76 struct trace_event;
  77
  78 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
  79                                       int flags, struct trace_event *event);
  80
  81 struct trace_event_functions {
  82         trace_print_func        trace;
  83         trace_print_func        raw;
  84         trace_print_func        hex;
  85         trace_print_func        binary;
  86 };
  87
  88 struct trace_event {
  89         struct hlist_node               node;
  90         struct list_head                list;
  91         int                             type;
  92         struct trace_event_functions    *funcs;
  93 };
  94
  95 extern int register_ftrace_event(struct trace_event *event);
  96 extern int unregister_ftrace_event(struct trace_event *event);
  97
  98 /* Return values for print_line callback */
  99 enum print_line_t {
 100         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 101         TRACE_TYPE_HANDLED      = 1,
 102         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 103         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 104 };
 105
 106 void tracing_generic_entry_update(struct trace_entry *entry,
 107                                   unsigned long flags,
 108                                   int pc);
 109 struct ring_buffer_event *
 110 trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
 111                                   int type, unsigned long len,
 112                                   unsigned long flags, int pc);
 113 void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
 114                                         struct ring_buffer_event *event,
 115                                         unsigned long flags, int pc);
 116 void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
 117                                        struct ring_buffer_event *event,
 118                                         unsigned long flags, int pc);
 119 void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 120                                          struct ring_buffer_event *event);
 121
 122 void tracing_record_cmdline(struct task_struct *tsk);
 123
 124 struct event_filter;
 125
 126 enum trace_reg {
 127         TRACE_REG_REGISTER,
 128         TRACE_REG_UNREGISTER,
 129         TRACE_REG_PERF_REGISTER,
 130         TRACE_REG_PERF_UNREGISTER,
 131 };
 132
 133 struct ftrace_event_call;
 134
 135 struct ftrace_event_class {
 136         char                    *system;
 137         void                    *probe;
 138 #ifdef CONFIG_PERF_EVENTS
 139         void                    *perf_probe;
 140 #endif
 141         int                     (*reg)(struct ftrace_event_call *event,
 142                                        enum trace_reg type);
 143         int                     (*define_fields)(struct ftrace_event_call *);
 144         struct list_head        *(*get_fields)(struct ftrace_event_call *);
 145         struct list_head        fields;
 146         int                     (*raw_init)(struct ftrace_event_call *);
 147 };
 148
 149 enum {
 150         TRACE_EVENT_FL_ENABLED_BIT,
 151         TRACE_EVENT_FL_FILTERED_BIT,
 152 };
 153
 154 enum {
 155         TRACE_EVENT_FL_ENABLED  = (1 << TRACE_EVENT_FL_ENABLED_BIT),
 156         TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT),
 157 };
 158
 159 struct ftrace_event_call {
 160         struct list_head        list;
 161         struct ftrace_event_class *class;
 162         char                    *name;
 163         struct dentry           *dir;
 164         struct trace_event      event;
 165         const char              *print_fmt;
 166         struct event_filter     *filter;
 167         void                    *mod;
 168         void                    *data;
 169
 170         /*
 171          * 32 bit flags:
 172          *   bit 1:             enabled
 173          *   bit 2:             filter_active
 174          *
 175          * Changes to flags must hold the event_mutex.
 176          *
 177          * Note: Reads of flags do not hold the event_mutex since
 178          * they occur in critical sections. But the way flags
 179          * is currently used, these changes do no affect the code
 180          * except that when a change is made, it may have a slight
 181          * delay in propagating the changes to other CPUs due to
 182          * caching and such.
 183          */
 184         unsigned int            flags;
 185
 186 #ifdef CONFIG_PERF_EVENTS
 187         int                     perf_refcount;
 188         struct hlist_head       *perf_events;
 189 #endif
 190 };
 191
 192 #define PERF_MAX_TRACE_SIZE     2048
 193
 194 #define MAX_FILTER_PRED         32
 195 #define MAX_FILTER_STR_VAL      256     /* Should handle KSYM_SYMBOL_LEN */
 196
 197 extern void destroy_preds(struct ftrace_event_call *call);
 198 extern int filter_match_preds(struct event_filter *filter, void *rec);
 199 extern int filter_current_check_discard(struct ring_buffer *buffer,
 200                                         struct ftrace_event_call *call,
 201                                         void *rec,
 202                                         struct ring_buffer_event *event);
 203
 204 enum {
 205         FILTER_OTHER = 0,
 206         FILTER_STATIC_STRING,
 207         FILTER_DYN_STRING,
 208         FILTER_PTR_STRING,
 209 };
 210
 211 extern int trace_event_raw_init(struct ftrace_event_call *call);
 212 extern int trace_define_field(struct ftrace_event_call *call, const char *type,
 213                               const char *name, int offset, int size,
 214                               int is_signed, int filter_type);
 215 extern int trace_add_event_call(struct ftrace_event_call *call);
 216 extern void trace_remove_event_call(struct ftrace_event_call *call);
 217
 218 #define is_signed_type(type)    (((type)(-1)) < 0)
 219
 220 int trace_set_clr_event(const char *system, const char *event, int set);
 221
 222 /*
 223  * The double __builtin_constant_p is because gcc will give us an error
 224  * if we try to allocate the static variable to fmt if it is not a
 225  * constant. Even with the outer if statement optimizing out.
 226  */
 227 #define event_trace_printk(ip, fmt, args...)                            \
 228 do {                                                                    \
 229         __trace_printk_check_format(fmt, ##args);                       \
 230         tracing_record_cmdline(current);                                \
 231         if (__builtin_constant_p(fmt)) {                                \
 232                 static const char *trace_printk_fmt                     \
 233                   __attribute__((section("__trace_printk_fmt"))) =      \
 234                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 235                                                                         \
 236                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 237         } else                                                          \
 238                 __trace_printk(ip, fmt, ##args);                        \
 239 } while (0)
 240
 241 #ifdef CONFIG_PERF_EVENTS
 242 struct perf_event;
 243
 244 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 245
 246 extern int  perf_trace_init(struct perf_event *event);
 247 extern void perf_trace_destroy(struct perf_event *event);
 248 extern int  perf_trace_enable(struct perf_event *event);
 249 extern void perf_trace_disable(struct perf_event *event);
 250 extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 251                                      char *filter_str);
 252 extern void ftrace_profile_free_filter(struct perf_event *event);
 253 extern void *perf_trace_buf_prepare(int size, unsigned short type,
 254                                     struct pt_regs *regs, int *rctxp);
 255
 256 static inline void
 257 perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
 258                        u64 count, struct pt_regs *regs, void *head)
 259 {
 260         perf_tp_event(addr, count, raw_data, size, regs, head);
 261         perf_swevent_put_recursion_context(rctx);
 262 }
 263 #endif
 264
 265 #endif /* _LINUX_FTRACE_EVENT_H */