liblttng-ust/lttng-bytecode.h

   1 #ifndef _LTTNG_BYTECODE_H
   2 #define _LTTNG_BYTECODE_H
   3
   4 /*
   5  * lttng-bytecode.h
   6  *
   7  * LTTng UST bytecode header.
   8  *
   9  * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  24  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  26  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  27  * SOFTWARE.
  28  */
  29
  30 #include <errno.h>
  31 #include <stdio.h>
  32 #include <stdbool.h>
  33 #include <helper.h>
  34 #include <lttng/ust-events.h>
  35 #include <lttng/ust-context-provider.h>
  36 #include <stdint.h>
  37 #include <assert.h>
  38 #include <errno.h>
  39 #include <string.h>
  40 #include <inttypes.h>
  41 #include <limits.h>
  42 #include <usterr-signal-safe.h>
  43 #include "bytecode.h"
  44
  45 /* Interpreter stack length, in number of entries */
  46 #define INTERPRETER_STACK_LEN   10      /* includes 2 dummy */
  47 #define INTERPRETER_STACK_EMPTY 1
  48
  49 #define BYTECODE_MAX_DATA_LEN   65536
  50
  51 #ifndef min_t
  52 #define min_t(type, a, b)       \
  53                 ((type) (a) < (type) (b) ? (type) (a) : (type) (b))
  54 #endif
  55
  56 #ifndef likely
  57 #define likely(x)       __builtin_expect(!!(x), 1)
  58 #endif
  59
  60 #ifndef unlikely
  61 #define unlikely(x)     __builtin_expect(!!(x), 0)
  62 #endif
  63
  64 #ifdef DEBUG
  65 #define dbg_printf(fmt, args...)                                \
  66         printf("[debug bytecode in %s:%s@%u] " fmt,             \
  67                 __FILE__, __func__, __LINE__, ## args)
  68 #else
  69 #define dbg_printf(fmt, args...)                                \
  70 do {                                                            \
  71         /* do nothing but check printf format */                \
  72         if (0)                                                  \
  73                 printf("[debug bytecode in %s:%s@%u] " fmt,     \
  74                         __FILE__, __func__, __LINE__, ## args); \
  75 } while (0)
  76 #endif
  77
  78 /* Linked bytecode. Child of struct lttng_bytecode_runtime. */
  79 struct bytecode_runtime {
  80         struct lttng_bytecode_runtime p;
  81         size_t data_len;
  82         size_t data_alloc_len;
  83         char *data;
  84         uint16_t len;
  85         char code[0];
  86 };
  87
  88 enum entry_type {
  89         REG_S64,
  90         REG_U64,
  91         REG_DOUBLE,
  92         REG_STRING,
  93         REG_STAR_GLOB_STRING,
  94         REG_UNKNOWN,
  95         REG_PTR,
  96 };
  97
  98 enum load_type {
  99         LOAD_ROOT_CONTEXT,
 100         LOAD_ROOT_APP_CONTEXT,
 101         LOAD_ROOT_PAYLOAD,
 102         LOAD_OBJECT,
 103 };
 104
 105 enum object_type {
 106         OBJECT_TYPE_S8,
 107         OBJECT_TYPE_S16,
 108         OBJECT_TYPE_S32,
 109         OBJECT_TYPE_S64,
 110         OBJECT_TYPE_U8,
 111         OBJECT_TYPE_U16,
 112         OBJECT_TYPE_U32,
 113         OBJECT_TYPE_U64,
 114
 115         OBJECT_TYPE_DOUBLE,
 116         OBJECT_TYPE_STRING,
 117         OBJECT_TYPE_STRING_SEQUENCE,
 118
 119         OBJECT_TYPE_SEQUENCE,
 120         OBJECT_TYPE_ARRAY,
 121         OBJECT_TYPE_STRUCT,
 122         OBJECT_TYPE_VARIANT,
 123
 124         OBJECT_TYPE_DYNAMIC,
 125 };
 126
 127 struct bytecode_get_index_data {
 128         uint64_t offset;        /* in bytes */
 129         size_t ctx_index;
 130         size_t array_len;
 131         /*
 132          * Field is only populated for LOAD_ROOT_CONTEXT, LOAD_ROOT_APP_CONTEXT
 133          * and LOAD_ROOT_PAYLOAD. Left NULL for LOAD_OBJECT, considering that the
 134          * interpreter needs to find it from the event fields and types to
 135          * support variants.
 136          */
 137         const struct lttng_event_field *field;
 138         struct {
 139                 size_t len;
 140                 enum object_type type;
 141                 bool rev_bo;    /* reverse byte order */
 142         } elem;
 143 };
 144
 145 /* Validation stack */
 146 struct vstack_load {
 147         enum load_type type;
 148         enum object_type object_type;
 149         const struct lttng_event_field *field;
 150         bool rev_bo;    /* reverse byte order */
 151 };
 152
 153 struct vstack_entry {
 154         enum entry_type type;
 155         struct vstack_load load;
 156 };
 157
 158 struct vstack {
 159         int top;        /* top of stack */
 160         struct vstack_entry e[INTERPRETER_STACK_LEN];
 161 };
 162
 163 static inline
 164 void vstack_init(struct vstack *stack)
 165 {
 166         stack->top = -1;
 167 }
 168
 169 static inline
 170 struct vstack_entry *vstack_ax(struct vstack *stack)
 171 {
 172         if (unlikely(stack->top < 0))
 173                 return NULL;
 174         return &stack->e[stack->top];
 175 }
 176
 177 static inline
 178 struct vstack_entry *vstack_bx(struct vstack *stack)
 179 {
 180         if (unlikely(stack->top < 1))
 181                 return NULL;
 182         return &stack->e[stack->top - 1];
 183 }
 184
 185 static inline
 186 int vstack_push(struct vstack *stack)
 187 {
 188         if (stack->top >= INTERPRETER_STACK_LEN - 1) {
 189                 ERR("Stack full\n");
 190                 return -EINVAL;
 191         }
 192         ++stack->top;
 193         return 0;
 194 }
 195
 196 static inline
 197 int vstack_pop(struct vstack *stack)
 198 {
 199         if (unlikely(stack->top < 0)) {
 200                 ERR("Stack empty\n");
 201                 return -EINVAL;
 202         }
 203         stack->top--;
 204         return 0;
 205 }
 206
 207 /* Execution stack */
 208 enum estack_string_literal_type {
 209         ESTACK_STRING_LITERAL_TYPE_NONE,
 210         ESTACK_STRING_LITERAL_TYPE_PLAIN,
 211         ESTACK_STRING_LITERAL_TYPE_STAR_GLOB,
 212 };
 213
 214 struct load_ptr {
 215         enum load_type type;
 216         enum object_type object_type;
 217         const void *ptr;
 218         size_t nr_elem;
 219         bool rev_bo;
 220         /* Temporary place-holders for contexts. */
 221         union {
 222                 int64_t s64;
 223                 uint64_t u64;
 224                 double d;
 225         } u;
 226         const struct lttng_event_field *field;
 227 };
 228
 229 struct estack_entry {
 230         enum entry_type type;   /* For dynamic typing. */
 231         union {
 232                 int64_t v;
 233                 double d;
 234
 235                 struct {
 236                         const char *str;
 237                         size_t seq_len;
 238                         enum estack_string_literal_type literal_type;
 239                 } s;
 240                 struct load_ptr ptr;
 241         } u;
 242 };
 243
 244 struct estack {
 245         int top;        /* top of stack */
 246         struct estack_entry e[INTERPRETER_STACK_LEN];
 247 };
 248
 249 /*
 250  * Always use aliased type for ax/bx (top of stack).
 251  * When ax/bx are S64, use aliased value.
 252  */
 253 #define estack_ax_v     ax
 254 #define estack_bx_v     bx
 255 #define estack_ax_t     ax_t
 256 #define estack_bx_t     bx_t
 257
 258 /*
 259  * ax and bx registers can hold either integer, double or string.
 260  */
 261 #define estack_ax(stack, top)                                   \
 262         ({                                                      \
 263                 assert((top) > INTERPRETER_STACK_EMPTY);        \
 264                 &(stack)->e[top];                               \
 265         })
 266
 267 #define estack_bx(stack, top)                                   \
 268         ({                                                      \
 269                 assert((top) > INTERPRETER_STACK_EMPTY + 1);    \
 270                 &(stack)->e[(top) - 1];                         \
 271         })
 272
 273 /*
 274  * Currently, only integers (REG_S64) can be pushed into the stack.
 275  */
 276 #define estack_push(stack, top, ax, bx, ax_t, bx_t)             \
 277         do {                                                    \
 278                 assert((top) < INTERPRETER_STACK_LEN - 1);      \
 279                 (stack)->e[(top) - 1].u.v = (bx);               \
 280                 (stack)->e[(top) - 1].type = (bx_t);            \
 281                 (bx) = (ax);                                    \
 282                 (bx_t) = (ax_t);                                \
 283                 ++(top);                                        \
 284         } while (0)
 285
 286 #define estack_pop(stack, top, ax, bx, ax_t, bx_t)              \
 287         do {                                                    \
 288                 assert((top) > INTERPRETER_STACK_EMPTY);        \
 289                 (ax) = (bx);                                    \
 290                 (ax_t) = (bx_t);                                \
 291                 (bx) = (stack)->e[(top) - 2].u.v;               \
 292                 (bx_t) = (stack)->e[(top) - 2].type;            \
 293                 (top)--;                                        \
 294         } while (0)
 295
 296 enum lttng_interpreter_type {
 297         LTTNG_INTERPRETER_TYPE_S64,
 298         LTTNG_INTERPRETER_TYPE_U64,
 299         LTTNG_INTERPRETER_TYPE_SIGNED_ENUM,
 300         LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM,
 301         LTTNG_INTERPRETER_TYPE_DOUBLE,
 302         LTTNG_INTERPRETER_TYPE_STRING,
 303         LTTNG_INTERPRETER_TYPE_SEQUENCE,
 304 };
 305
 306 /*
 307  * Represents the output parameter of the lttng interpreter.
 308  * Currently capturable field classes are integer, double, string and sequence
 309  * of integer.
 310  */
 311 struct lttng_interpreter_output {
 312         enum lttng_interpreter_type type;
 313         union {
 314                 int64_t s;
 315                 uint64_t u;
 316                 double d;
 317
 318                 struct {
 319                         const char *str;
 320                         size_t len;
 321                 } str;
 322                 struct {
 323                         const void *ptr;
 324                         size_t nr_elem;
 325
 326                         /* Inner type. */
 327                         const struct lttng_type *nested_type;
 328                 } sequence;
 329         } u;
 330 };
 331
 332 const char *print_op(enum bytecode_op op);
 333
 334 void lttng_bytecode_filter_sync_state(struct lttng_bytecode_runtime *runtime);
 335
 336 int lttng_bytecode_validate(struct bytecode_runtime *bytecode);
 337 int lttng_bytecode_specialize(const struct lttng_event_desc *event_desc,
 338                 struct bytecode_runtime *bytecode);
 339
 340 uint64_t lttng_bytecode_filter_interpret_false(void *filter_data,
 341                 const char *filter_stack_data);
 342 uint64_t lttng_bytecode_filter_interpret(void *filter_data,
 343                 const char *filter_stack_data);
 344
 345 #endif /* _LTTNG_BYTECODE_H */