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 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 const char *ftrace_print_hex_seq(struct trace_seq *p,
  27                                  const unsigned char *buf, int len);
  28
  29 /*
  30  * The trace entry - the most basic unit of tracing. This is what
  31  * is printed in the end as a single line in the trace output, such as:
  32  *
  33  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  34  */
  35 struct trace_entry {
  36         unsigned short          type;
  37         unsigned char           flags;
  38         unsigned char           preempt_count;
  39         int                     pid;
  40         int                     lock_depth;
  41 };
  42
  43 #define FTRACE_MAX_EVENT                                                \
  44         ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  45
  46 /*
  47  * Trace iterator - used by printout routines who present trace
  48  * results to users and which routines might sleep, etc:
  49  */
  50 struct trace_iterator {
  51         struct trace_array      *tr;
  52         struct tracer           *trace;
  53         void                    *private;
  54         int                     cpu_file;
  55         struct mutex            mutex;
  56         struct ring_buffer_iter *buffer_iter[NR_CPUS];
  57         unsigned long           iter_flags;
  58
  59         /* trace_seq for __print_flags() and __print_symbolic() etc. */
  60         struct trace_seq        tmp_seq;
  61
  62         /* The below is zeroed out in pipe_read */
  63         struct trace_seq        seq;
  64         struct trace_entry      *ent;
  65         unsigned long           lost_events;
  66         int                     leftover;
  67         int                     cpu;
  68         u64                     ts;
  69
  70         loff_t                  pos;
  71         long                    idx;
  72
  73         cpumask_var_t           started;
  74 };
  75
  76
  77 struct trace_event;
  78
  79 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
  80                                       int flags, struct trace_event *event);
  81
  82 struct trace_event_functions {
  83         trace_print_func        trace;
  84         trace_print_func        raw;
  85         trace_print_func        hex;
  86         trace_print_func        binary;
  87 };
  88
  89 struct trace_event {
  90         struct hlist_node               node;
  91         struct list_head                list;
  92         int                             type;
  93         struct trace_event_functions    *funcs;
  94 };
  95
  96 extern int register_ftrace_event(struct trace_event *event);
  97 extern int unregister_ftrace_event(struct trace_event *event);
  98
  99 /* Return values for print_line callback */
 100 enum print_line_t {
 101         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 102         TRACE_TYPE_HANDLED      = 1,
 103         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 104         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 105 };
 106
 107 void tracing_generic_entry_update(struct trace_entry *entry,
 108                                   unsigned long flags,
 109                                   int pc);
 110 struct ring_buffer_event *
 111 trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
 112                                   int type, unsigned long len,
 113                                   unsigned long flags, int pc);
 114 void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
 115                                         struct ring_buffer_event *event,
 116                                         unsigned long flags, int pc);
 117 void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
 118                                        struct ring_buffer_event *event,
 119                                         unsigned long flags, int pc);
 120 void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 121                                          struct ring_buffer_event *event);
 122
 123 void tracing_record_cmdline(struct task_struct *tsk);
 124
 125 struct event_filter;
 126
 127 enum trace_reg {
 128         TRACE_REG_REGISTER,
 129         TRACE_REG_UNREGISTER,
 130         TRACE_REG_PERF_REGISTER,
 131         TRACE_REG_PERF_UNREGISTER,
 132 };
 133
 134 struct ftrace_event_call;
 135
 136 struct ftrace_event_class {
 137         char                    *system;
 138         void                    *probe;
 139 #ifdef CONFIG_PERF_EVENTS
 140         void                    *perf_probe;
 141 #endif
 142         int                     (*reg)(struct ftrace_event_call *event,
 143                                        enum trace_reg type);
 144         int                     (*define_fields)(struct ftrace_event_call *);
 145         struct list_head        *(*get_fields)(struct ftrace_event_call *);
 146         struct list_head        fields;
 147         int                     (*raw_init)(struct ftrace_event_call *);
 148 };
 149
 150 extern int ftrace_event_reg(struct ftrace_event_call *event,
 151                             enum trace_reg type);
 152
 153 enum {
 154         TRACE_EVENT_FL_ENABLED_BIT,
 155         TRACE_EVENT_FL_FILTERED_BIT,
 156         TRACE_EVENT_FL_RECORDED_CMD_BIT,
 157 };
 158
 159 enum {
 160         TRACE_EVENT_FL_ENABLED          = (1 << TRACE_EVENT_FL_ENABLED_BIT),
 161         TRACE_EVENT_FL_FILTERED         = (1 << TRACE_EVENT_FL_FILTERED_BIT),
 162         TRACE_EVENT_FL_RECORDED_CMD     = (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT),
 163 };
 164
 165 struct ftrace_event_call {
 166         struct list_head        list;
 167         struct ftrace_event_class *class;
 168         char                    *name;
 169         struct dentry           *dir;
 170         struct trace_event      event;
 171         const char              *print_fmt;
 172         struct event_filter     *filter;
 173         void                    *mod;
 174         void                    *data;
 175
 176         /*
 177          * 32 bit flags:
 178          *   bit 1:             enabled
 179          *   bit 2:             filter_active
 180          *   bit 3:             enabled cmd record
 181          *
 182          * Changes to flags must hold the event_mutex.
 183          *
 184          * Note: Reads of flags do not hold the event_mutex since
 185          * they occur in critical sections. But the way flags
 186          * is currently used, these changes do no affect the code
 187          * except that when a change is made, it may have a slight
 188          * delay in propagating the changes to other CPUs due to
 189          * caching and such.
 190          */
 191         unsigned int            flags;
 192
 193 #ifdef CONFIG_PERF_EVENTS
 194         int                     perf_refcount;
 195         struct hlist_head       *perf_events;
 196 #endif
 197 };
 198
 199 #define PERF_MAX_TRACE_SIZE     2048
 200
 201 #define MAX_FILTER_PRED         32
 202 #define MAX_FILTER_STR_VAL      256     /* Should handle KSYM_SYMBOL_LEN */
 203
 204 extern void destroy_preds(struct ftrace_event_call *call);
 205 extern int filter_match_preds(struct event_filter *filter, void *rec);
 206 extern int filter_current_check_discard(struct ring_buffer *buffer,
 207                                         struct ftrace_event_call *call,
 208                                         void *rec,
 209                                         struct ring_buffer_event *event);
 210
 211 enum {
 212         FILTER_OTHER = 0,
 213         FILTER_STATIC_STRING,
 214         FILTER_DYN_STRING,
 215         FILTER_PTR_STRING,
 216 };
 217
 218 extern int trace_event_raw_init(struct ftrace_event_call *call);
 219 extern int trace_define_field(struct ftrace_event_call *call, const char *type,
 220                               const char *name, int offset, int size,
 221                               int is_signed, int filter_type);
 222 extern int trace_add_event_call(struct ftrace_event_call *call);
 223 extern void trace_remove_event_call(struct ftrace_event_call *call);
 224
 225 #define is_signed_type(type)    (((type)(-1)) < 0)
 226
 227 int trace_set_clr_event(const char *system, const char *event, int set);
 228
 229 /*
 230  * The double __builtin_constant_p is because gcc will give us an error
 231  * if we try to allocate the static variable to fmt if it is not a
 232  * constant. Even with the outer if statement optimizing out.
 233  */
 234 #define event_trace_printk(ip, fmt, args...)                            \
 235 do {                                                                    \
 236         __trace_printk_check_format(fmt, ##args);                       \
 237         tracing_record_cmdline(current);                                \
 238         if (__builtin_constant_p(fmt)) {                                \
 239                 static const char *trace_printk_fmt                     \
 240                   __attribute__((section("__trace_printk_fmt"))) =      \
 241                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 242                                                                         \
 243                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 244         } else                                                          \
 245                 __trace_printk(ip, fmt, ##args);                        \
 246 } while (0)
 247
 248 #ifdef CONFIG_PERF_EVENTS
 249 struct perf_event;
 250
 251 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 252
 253 extern int  perf_trace_init(struct perf_event *event);
 254 extern void perf_trace_destroy(struct perf_event *event);
 255 extern int  perf_trace_enable(struct perf_event *event);
 256 extern void perf_trace_disable(struct perf_event *event);
 257 extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 258                                      char *filter_str);
 259 extern void ftrace_profile_free_filter(struct perf_event *event);
 260 extern void *perf_trace_buf_prepare(int size, unsigned short type,
 261                                     struct pt_regs *regs, int *rctxp);
 262
 263 static inline void
 264 perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
 265                        u64 count, struct pt_regs *regs, void *head)
 266 {
 267         perf_tp_event(addr, count, raw_data, size, regs, head, rctx);
 268 }
 269 #endif
 270
 271 #endif /* _LINUX_FTRACE_EVENT_H */