ltt-tracer.h

   1 /*
   2  * Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
   3  *
   4  * This contains the definitions for the Linux Trace Toolkit tracer.
   5  *
   6  * Dual LGPL v2.1/GPL v2 license.
   7  */
   8
   9 #ifndef _LTT_TRACER_H
  10 #define _LTT_TRACER_H
  11
  12 #include <stdarg.h>
  13 #include <linux/types.h>
  14 #include <linux/limits.h>
  15 #include <linux/list.h>
  16 #include <linux/cache.h>
  17 #include <linux/timex.h>
  18 #include <linux/wait.h>
  19 #include <asm/atomic.h>
  20 #include <asm/local.h>
  21
  22 #include "wrapper/trace-clock.h"
  23 #include "ltt-tracer-core.h"
  24 #include "ltt-events.h"
  25
  26 #ifndef CHAR_BIT
  27 #define CHAR_BIT 8
  28 #endif
  29
  30 /* Number of bytes to log with a read/write event */
  31 #define LTT_LOG_RW_SIZE                 32L
  32
  33 /* Maximum number of callbacks per marker */
  34 #define LTT_NR_CALLBACKS        10
  35
  36 struct ltt_serialize_closure;
  37
  38 /* Serialization callback */
  39 typedef size_t (*ltt_serialize_cb)(struct lib_ring_buffer *buf,
  40                                    size_t buf_offset,
  41                                    struct ltt_serialize_closure *closure,
  42                                    void *serialize_private,
  43                                    unsigned int stack_pos_ctx,
  44                                    int *largest_align,
  45                                    const char *fmt, va_list *args);
  46
  47 struct ltt_serialize_closure {
  48         ltt_serialize_cb *callbacks;
  49         long cb_args[LTT_NR_CALLBACKS];
  50         unsigned int cb_idx;
  51 };
  52
  53 size_t ltt_serialize_data(struct lib_ring_buffer *buf, size_t buf_offset,
  54                           struct ltt_serialize_closure *closure,
  55                           void *serialize_private, unsigned int stack_pos_ctx,
  56                           int *largest_align, const char *fmt, va_list *args);
  57
  58 enum ltt_channels {
  59         LTT_CHANNEL_METADATA,
  60         LTT_CHANNEL_FD_STATE,
  61         LTT_CHANNEL_GLOBAL_STATE,
  62         LTT_CHANNEL_IRQ_STATE,
  63         LTT_CHANNEL_MODULE_STATE,
  64         LTT_CHANNEL_NETIF_STATE,
  65         LTT_CHANNEL_SOFTIRQ_STATE,
  66         LTT_CHANNEL_SWAP_STATE,
  67         LTT_CHANNEL_SYSCALL_STATE,
  68         LTT_CHANNEL_TASK_STATE,
  69         LTT_CHANNEL_VM_STATE,
  70         LTT_CHANNEL_FS,
  71         LTT_CHANNEL_INPUT,
  72         LTT_CHANNEL_IPC,
  73         LTT_CHANNEL_KERNEL,
  74         LTT_CHANNEL_MM,
  75         LTT_CHANNEL_RCU,
  76         LTT_CHANNEL_DEFAULT,
  77 };
  78
  79 /*
  80  * Hardcoded event headers
  81  *
  82  * event header for a trace with active heartbeat : 27 bits timestamps
  83  *
  84  * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
  85  * trace alignment value must be done.
  86  *
  87  * Remember that the C compiler does align each member on the boundary
  88  * equivalent to their own size.
  89  *
  90  * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
  91  * bytes aligned, so the buffer header and trace header are aligned.
  92  *
  93  * Event headers are aligned depending on the trace alignment option.
  94  *
  95  * Note using C structure bitfields for cross-endianness and portability
  96  * concerns.
  97  */
  98
  99 #define LTT_RESERVED_EVENTS     3
 100 #define LTT_EVENT_BITS          5
 101 #define LTT_FREE_EVENTS         ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
 102 #define LTT_TSC_BITS            27
 103 #define LTT_TSC_MASK            ((1 << LTT_TSC_BITS) - 1)
 104
 105 struct event_header {
 106         u32 id_time;            /* 5 bits event id (MSB); 27 bits time (LSB) */
 107 };
 108
 109 /* Reservation flags */
 110 #define LTT_RFLAG_ID                    (1 << 0)
 111 #define LTT_RFLAG_ID_SIZE               (1 << 1)
 112 #define LTT_RFLAG_ID_SIZE_TSC           (1 << 2)
 113
 114 #define LTT_MAX_SMALL_SIZE              0xFFFFU
 115
 116 #ifdef RING_BUFFER_ALIGN
 117 static inline
 118 size_t ltt_get_header_alignment(void)
 119 {
 120         return sizeof(struct event_header) * CHAR_BIT;
 121 }
 122
 123 #define ltt_alignof(type)       __alignof__(type)
 124 #else
 125 static inline
 126 size_t ltt_get_header_alignment(void)
 127 {
 128         return CHAR_BIT;
 129 }
 130
 131 #define ltt_alignof(type)       1
 132 #endif
 133
 134 /* Tracer properties */
 135 #define CTF_MAGIC_NUMBER                0xC1FC1FC1
 136 #define TSDL_MAGIC_NUMBER               0x75D11D57
 137 #define CTF_VERSION_MAJOR               0
 138 #define CTF_VERSION_MINOR               1
 139
 140 /*
 141  * Number of milliseconds to retry before failing metadata writes on buffer full
 142  * condition. (10 seconds)
 143  */
 144 #define LTTNG_METADATA_TIMEOUT_MSEC     10000
 145
 146 /*
 147  * Size reserved for high priority events (interrupts, NMI, BH) at the end of a
 148  * nearly full buffer. User space won't use this last amount of space when in
 149  * blocking mode. This space also includes the event header that would be
 150  * written by this user space event.
 151  */
 152 #define LTT_RESERVE_CRITICAL            4096
 153
 154 /* Register and unregister function pointers */
 155
 156 enum ltt_module_function {
 157         LTT_FUNCTION_RUN_FILTER,
 158         LTT_FUNCTION_FILTER_CONTROL,
 159         LTT_FUNCTION_STATEDUMP
 160 };
 161
 162 extern int ltt_module_register(enum ltt_module_function name, void *function,
 163                                struct module *owner);
 164 extern void ltt_module_unregister(enum ltt_module_function name);
 165
 166 /* Exported control function */
 167
 168 void ltt_core_register(int (*function)(u8, void *));
 169
 170 void ltt_core_unregister(void);
 171
 172 extern
 173 void ltt_statedump_register_kprobes_dump(void (*callback)(void *call_data));
 174 extern
 175 void ltt_statedump_unregister_kprobes_dump(void (*callback)(void *call_data));
 176
 177 extern void ltt_dump_softirq_vec(void *call_data);
 178
 179 #ifdef CONFIG_HAVE_LTT_DUMP_TABLES
 180 extern void ltt_dump_sys_call_table(void *call_data);
 181 extern void ltt_dump_idt_table(void *call_data);
 182 #else
 183 static inline void ltt_dump_sys_call_table(void *call_data)
 184 {
 185 }
 186
 187 static inline void ltt_dump_idt_table(void *call_data)
 188 {
 189 }
 190 #endif
 191
 192 #endif /* _LTT_TRACER_H */