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 struct trace_print_flags_u64 {
  20         unsigned long long      mask;
  21         const char              *name;
  22 };
  23
  24 const char *ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
  25                                    unsigned long flags,
  26                                    const struct trace_print_flags *flag_array);
  27
  28 const char *ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
  29                                      const struct trace_print_flags *symbol_array);
  30
  31 #if BITS_PER_LONG == 32
  32 const char *ftrace_print_symbols_seq_u64(struct trace_seq *p,
  33                                          unsigned long long val,
  34                                          const struct trace_print_flags_u64
  35                                                                  *symbol_array);
  36 #endif
  37
  38 const char *ftrace_print_hex_seq(struct trace_seq *p,
  39                                  const unsigned char *buf, int len);
  40
  41 /*
  42  * The trace entry - the most basic unit of tracing. This is what
  43  * is printed in the end as a single line in the trace output, such as:
  44  *
  45  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  46  */
  47 struct trace_entry {
  48         unsigned short          type;
  49         unsigned char           flags;
  50         unsigned char           preempt_count;
  51         int                     pid;
  52 };
  53
  54 #define FTRACE_MAX_EVENT                                                \
  55         ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  56
  57 /*
  58  * Trace iterator - used by printout routines who present trace
  59  * results to users and which routines might sleep, etc:
  60  */
  61 struct trace_iterator {
  62         struct trace_array      *tr;
  63         struct tracer           *trace;
  64         void                    *private;
  65         int                     cpu_file;
  66         struct mutex            mutex;
  67         struct ring_buffer_iter **buffer_iter;
  68         unsigned long           iter_flags;
  69
  70         /* trace_seq for __print_flags() and __print_symbolic() etc. */
  71         struct trace_seq        tmp_seq;
  72
  73         /* The below is zeroed out in pipe_read */
  74         struct trace_seq        seq;
  75         struct trace_entry      *ent;
  76         unsigned long           lost_events;
  77         int                     leftover;
  78         int                     ent_size;
  79         int                     cpu;
  80         u64                     ts;
  81
  82         loff_t                  pos;
  83         long                    idx;
  84
  85         cpumask_var_t           started;
  86
  87         /* it's true when current open file is snapshot */
  88         bool                    snapshot;
  89 };
  90
  91 enum trace_iter_flags {
  92         TRACE_FILE_LAT_FMT      = 1,
  93         TRACE_FILE_ANNOTATE     = 2,
  94         TRACE_FILE_TIME_IN_NS   = 4,
  95 };
  96
  97
  98 struct trace_event;
  99
 100 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
 101                                       int flags, struct trace_event *event);
 102
 103 struct trace_event_functions {
 104         trace_print_func        trace;
 105         trace_print_func        raw;
 106         trace_print_func        hex;
 107         trace_print_func        binary;
 108 };
 109
 110 struct trace_event {
 111         struct hlist_node               node;
 112         struct list_head                list;
 113         int                             type;
 114         struct trace_event_functions    *funcs;
 115 };
 116
 117 extern int register_ftrace_event(struct trace_event *event);
 118 extern int unregister_ftrace_event(struct trace_event *event);
 119
 120 /* Return values for print_line callback */
 121 enum print_line_t {
 122         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 123         TRACE_TYPE_HANDLED      = 1,
 124         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 125         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 126 };
 127
 128 void tracing_generic_entry_update(struct trace_entry *entry,
 129                                   unsigned long flags,
 130                                   int pc);
 131 struct ring_buffer_event *
 132 trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
 133                                   int type, unsigned long len,
 134                                   unsigned long flags, int pc);
 135 void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
 136                                         struct ring_buffer_event *event,
 137                                         unsigned long flags, int pc);
 138 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
 139                                 struct ring_buffer_event *event,
 140                                 unsigned long flags, int pc);
 141 void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer,
 142                                      struct ring_buffer_event *event,
 143                                      unsigned long flags, int pc,
 144                                      struct pt_regs *regs);
 145 void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 146                                          struct ring_buffer_event *event);
 147
 148 void tracing_record_cmdline(struct task_struct *tsk);
 149
 150 struct event_filter;
 151
 152 enum trace_reg {
 153         TRACE_REG_REGISTER,
 154         TRACE_REG_UNREGISTER,
 155 #ifdef CONFIG_PERF_EVENTS
 156         TRACE_REG_PERF_REGISTER,
 157         TRACE_REG_PERF_UNREGISTER,
 158         TRACE_REG_PERF_OPEN,
 159         TRACE_REG_PERF_CLOSE,
 160         TRACE_REG_PERF_ADD,
 161         TRACE_REG_PERF_DEL,
 162 #endif
 163 };
 164
 165 struct ftrace_event_call;
 166
 167 struct ftrace_event_class {
 168         char                    *system;
 169         void                    *probe;
 170 #ifdef CONFIG_PERF_EVENTS
 171         void                    *perf_probe;
 172 #endif
 173         int                     (*reg)(struct ftrace_event_call *event,
 174                                        enum trace_reg type, void *data);
 175         int                     (*define_fields)(struct ftrace_event_call *);
 176         struct list_head        *(*get_fields)(struct ftrace_event_call *);
 177         struct list_head        fields;
 178         int                     (*raw_init)(struct ftrace_event_call *);
 179 };
 180
 181 extern int ftrace_event_reg(struct ftrace_event_call *event,
 182                             enum trace_reg type, void *data);
 183
 184 enum {
 185         TRACE_EVENT_FL_ENABLED_BIT,
 186         TRACE_EVENT_FL_FILTERED_BIT,
 187         TRACE_EVENT_FL_RECORDED_CMD_BIT,
 188         TRACE_EVENT_FL_CAP_ANY_BIT,
 189         TRACE_EVENT_FL_NO_SET_FILTER_BIT,
 190         TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
 191 };
 192
 193 enum {
 194         TRACE_EVENT_FL_ENABLED          = (1 << TRACE_EVENT_FL_ENABLED_BIT),
 195         TRACE_EVENT_FL_FILTERED         = (1 << TRACE_EVENT_FL_FILTERED_BIT),
 196         TRACE_EVENT_FL_RECORDED_CMD     = (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT),
 197         TRACE_EVENT_FL_CAP_ANY          = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
 198         TRACE_EVENT_FL_NO_SET_FILTER    = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
 199         TRACE_EVENT_FL_IGNORE_ENABLE    = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
 200 };
 201
 202 struct ftrace_event_call {
 203         struct list_head        list;
 204         struct ftrace_event_class *class;
 205         char                    *name;
 206         struct dentry           *dir;
 207         struct trace_event      event;
 208         const char              *print_fmt;
 209         struct event_filter     *filter;
 210         void                    *mod;
 211         void                    *data;
 212
 213         /*
 214          * 32 bit flags:
 215          *   bit 1:             enabled
 216          *   bit 2:             filter_active
 217          *   bit 3:             enabled cmd record
 218          *   bit 4:             allow trace by non root (cap any)
 219          *   bit 5:             failed to apply filter
 220          *   bit 6:             ftrace internal event (do not enable)
 221          *
 222          * Changes to flags must hold the event_mutex.
 223          *
 224          * Note: Reads of flags do not hold the event_mutex since
 225          * they occur in critical sections. But the way flags
 226          * is currently used, these changes do no affect the code
 227          * except that when a change is made, it may have a slight
 228          * delay in propagating the changes to other CPUs due to
 229          * caching and such.
 230          */
 231         unsigned int            flags;
 232
 233 #ifdef CONFIG_PERF_EVENTS
 234         int                             perf_refcount;
 235         struct hlist_head __percpu      *perf_events;
 236 #endif
 237 };
 238
 239 #define __TRACE_EVENT_FLAGS(name, value)                                \
 240         static int __init trace_init_flags_##name(void)                 \
 241         {                                                               \
 242                 event_##name.flags = value;                             \
 243                 return 0;                                               \
 244         }                                                               \
 245         early_initcall(trace_init_flags_##name);
 246
 247 #define PERF_MAX_TRACE_SIZE     2048
 248
 249 #define MAX_FILTER_STR_VAL      256     /* Should handle KSYM_SYMBOL_LEN */
 250
 251 extern void destroy_preds(struct ftrace_event_call *call);
 252 extern int filter_match_preds(struct event_filter *filter, void *rec);
 253 extern int filter_current_check_discard(struct ring_buffer *buffer,
 254                                         struct ftrace_event_call *call,
 255                                         void *rec,
 256                                         struct ring_buffer_event *event);
 257
 258 enum {
 259         FILTER_OTHER = 0,
 260         FILTER_STATIC_STRING,
 261         FILTER_DYN_STRING,
 262         FILTER_PTR_STRING,
 263         FILTER_TRACE_FN,
 264 };
 265
 266 #define EVENT_STORAGE_SIZE 128
 267 extern struct mutex event_storage_mutex;
 268 extern char event_storage[EVENT_STORAGE_SIZE];
 269
 270 extern int trace_event_raw_init(struct ftrace_event_call *call);
 271 extern int trace_define_field(struct ftrace_event_call *call, const char *type,
 272                               const char *name, int offset, int size,
 273                               int is_signed, int filter_type);
 274 extern int trace_add_event_call(struct ftrace_event_call *call);
 275 extern void trace_remove_event_call(struct ftrace_event_call *call);
 276
 277 #define is_signed_type(type)    (((type)(-1)) < (type)0)
 278
 279 int trace_set_clr_event(const char *system, const char *event, int set);
 280
 281 /*
 282  * The double __builtin_constant_p is because gcc will give us an error
 283  * if we try to allocate the static variable to fmt if it is not a
 284  * constant. Even with the outer if statement optimizing out.
 285  */
 286 #define event_trace_printk(ip, fmt, args...)                            \
 287 do {                                                                    \
 288         __trace_printk_check_format(fmt, ##args);                       \
 289         tracing_record_cmdline(current);                                \
 290         if (__builtin_constant_p(fmt)) {                                \
 291                 static const char *trace_printk_fmt                     \
 292                   __attribute__((section("__trace_printk_fmt"))) =      \
 293                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 294                                                                         \
 295                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 296         } else                                                          \
 297                 __trace_printk(ip, fmt, ##args);                        \
 298 } while (0)
 299
 300 #ifdef CONFIG_PERF_EVENTS
 301 struct perf_event;
 302
 303 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 304
 305 extern int  perf_trace_init(struct perf_event *event);
 306 extern void perf_trace_destroy(struct perf_event *event);
 307 extern int  perf_trace_add(struct perf_event *event, int flags);
 308 extern void perf_trace_del(struct perf_event *event, int flags);
 309 extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 310                                      char *filter_str);
 311 extern void ftrace_profile_free_filter(struct perf_event *event);
 312 extern void *perf_trace_buf_prepare(int size, unsigned short type,
 313                                     struct pt_regs *regs, int *rctxp);
 314
 315 static inline void
 316 perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
 317                        u64 count, struct pt_regs *regs, void *head,
 318                        struct task_struct *task)
 319 {
 320         perf_tp_event(addr, count, raw_data, size, regs, head, rctx, task);
 321 }
 322 #endif
 323
 324 #endif /* _LINUX_FTRACE_EVENT_H */