| 1 | #ifndef _LTTNG_FILTER_H |
| 2 | #define _LTTNG_FILTER_H |
| 3 | |
| 4 | /* |
| 5 | * lttng-filter.h |
| 6 | * |
| 7 | * LTTng UST filter 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 <helper.h> |
| 33 | #include <lttng/ust-events.h> |
| 34 | #include <lttng/ust-context-provider.h> |
| 35 | #include <stdint.h> |
| 36 | #include <assert.h> |
| 37 | #include <errno.h> |
| 38 | #include <string.h> |
| 39 | #include <inttypes.h> |
| 40 | #include <limits.h> |
| 41 | #include <usterr-signal-safe.h> |
| 42 | #include "filter-bytecode.h" |
| 43 | |
| 44 | /* Filter stack length, in number of entries */ |
| 45 | #define FILTER_STACK_LEN 10 /* includes 2 dummy */ |
| 46 | #define FILTER_STACK_EMPTY 1 |
| 47 | |
| 48 | #define FILTER_MAX_DATA_LEN 65536 |
| 49 | |
| 50 | #ifndef min_t |
| 51 | #define min_t(type, a, b) \ |
| 52 | ((type) (a) < (type) (b) ? (type) (a) : (type) (b)) |
| 53 | #endif |
| 54 | |
| 55 | #ifndef likely |
| 56 | #define likely(x) __builtin_expect(!!(x), 1) |
| 57 | #endif |
| 58 | |
| 59 | #ifndef unlikely |
| 60 | #define unlikely(x) __builtin_expect(!!(x), 0) |
| 61 | #endif |
| 62 | |
| 63 | #ifdef DEBUG |
| 64 | #define dbg_printf(fmt, args...) \ |
| 65 | printf("[debug bytecode in %s:%s@%u] " fmt, \ |
| 66 | __FILE__, __func__, __LINE__, ## args) |
| 67 | #else |
| 68 | #define dbg_printf(fmt, args...) \ |
| 69 | do { \ |
| 70 | /* do nothing but check printf format */ \ |
| 71 | if (0) \ |
| 72 | printf("[debug bytecode in %s:%s@%u] " fmt, \ |
| 73 | __FILE__, __func__, __LINE__, ## args); \ |
| 74 | } while (0) |
| 75 | #endif |
| 76 | |
| 77 | /* Linked bytecode. Child of struct lttng_bytecode_runtime. */ |
| 78 | struct bytecode_runtime { |
| 79 | struct lttng_bytecode_runtime p; |
| 80 | size_t data_len; |
| 81 | size_t data_alloc_len; |
| 82 | char *data; |
| 83 | uint16_t len; |
| 84 | char code[0]; |
| 85 | }; |
| 86 | |
| 87 | enum entry_type { |
| 88 | REG_S64, |
| 89 | REG_DOUBLE, |
| 90 | REG_STRING, |
| 91 | REG_STAR_GLOB_STRING, |
| 92 | REG_UNKNOWN, |
| 93 | REG_PTR, |
| 94 | }; |
| 95 | |
| 96 | enum load_type { |
| 97 | LOAD_ROOT_CONTEXT, |
| 98 | LOAD_ROOT_APP_CONTEXT, |
| 99 | LOAD_ROOT_PAYLOAD, |
| 100 | LOAD_OBJECT, |
| 101 | }; |
| 102 | |
| 103 | enum object_type { |
| 104 | OBJECT_TYPE_S8, |
| 105 | OBJECT_TYPE_S16, |
| 106 | OBJECT_TYPE_S32, |
| 107 | OBJECT_TYPE_S64, |
| 108 | OBJECT_TYPE_U8, |
| 109 | OBJECT_TYPE_U16, |
| 110 | OBJECT_TYPE_U32, |
| 111 | OBJECT_TYPE_U64, |
| 112 | |
| 113 | OBJECT_TYPE_DOUBLE, |
| 114 | OBJECT_TYPE_STRING, |
| 115 | OBJECT_TYPE_STRING_SEQUENCE, |
| 116 | |
| 117 | OBJECT_TYPE_SEQUENCE, |
| 118 | OBJECT_TYPE_ARRAY, |
| 119 | OBJECT_TYPE_STRUCT, |
| 120 | OBJECT_TYPE_VARIANT, |
| 121 | |
| 122 | OBJECT_TYPE_DYNAMIC, |
| 123 | }; |
| 124 | |
| 125 | struct filter_get_index_data { |
| 126 | uint64_t offset; /* in bytes */ |
| 127 | size_t ctx_index; |
| 128 | size_t array_len; |
| 129 | struct { |
| 130 | size_t len; |
| 131 | enum object_type type; |
| 132 | bool rev_bo; /* reverse byte order */ |
| 133 | } elem; |
| 134 | }; |
| 135 | |
| 136 | /* Validation stack */ |
| 137 | struct vstack_load { |
| 138 | enum load_type type; |
| 139 | enum object_type object_type; |
| 140 | const struct lttng_event_field *field; |
| 141 | bool rev_bo; /* reverse byte order */ |
| 142 | }; |
| 143 | |
| 144 | struct vstack_entry { |
| 145 | enum entry_type type; |
| 146 | struct vstack_load load; |
| 147 | }; |
| 148 | |
| 149 | struct vstack { |
| 150 | int top; /* top of stack */ |
| 151 | struct vstack_entry e[FILTER_STACK_LEN]; |
| 152 | }; |
| 153 | |
| 154 | static inline |
| 155 | void vstack_init(struct vstack *stack) |
| 156 | { |
| 157 | stack->top = -1; |
| 158 | } |
| 159 | |
| 160 | static inline |
| 161 | struct vstack_entry *vstack_ax(struct vstack *stack) |
| 162 | { |
| 163 | if (unlikely(stack->top < 0)) |
| 164 | return NULL; |
| 165 | return &stack->e[stack->top]; |
| 166 | } |
| 167 | |
| 168 | static inline |
| 169 | struct vstack_entry *vstack_bx(struct vstack *stack) |
| 170 | { |
| 171 | if (unlikely(stack->top < 1)) |
| 172 | return NULL; |
| 173 | return &stack->e[stack->top - 1]; |
| 174 | } |
| 175 | |
| 176 | static inline |
| 177 | int vstack_push(struct vstack *stack) |
| 178 | { |
| 179 | if (stack->top >= FILTER_STACK_LEN - 1) { |
| 180 | ERR("Stack full\n"); |
| 181 | return -EINVAL; |
| 182 | } |
| 183 | ++stack->top; |
| 184 | return 0; |
| 185 | } |
| 186 | |
| 187 | static inline |
| 188 | int vstack_pop(struct vstack *stack) |
| 189 | { |
| 190 | if (unlikely(stack->top < 0)) { |
| 191 | ERR("Stack empty\n"); |
| 192 | return -EINVAL; |
| 193 | } |
| 194 | stack->top--; |
| 195 | return 0; |
| 196 | } |
| 197 | |
| 198 | /* Execution stack */ |
| 199 | enum estack_string_literal_type { |
| 200 | ESTACK_STRING_LITERAL_TYPE_NONE, |
| 201 | ESTACK_STRING_LITERAL_TYPE_PLAIN, |
| 202 | ESTACK_STRING_LITERAL_TYPE_STAR_GLOB, |
| 203 | }; |
| 204 | |
| 205 | struct load_ptr { |
| 206 | enum load_type type; |
| 207 | enum object_type object_type; |
| 208 | const void *ptr; |
| 209 | bool rev_bo; |
| 210 | /* Temporary place-holders for contexts. */ |
| 211 | union { |
| 212 | int64_t s64; |
| 213 | uint64_t u64; |
| 214 | double d; |
| 215 | } u; |
| 216 | /* |
| 217 | * "field" is only needed when nested under a variant, in which |
| 218 | * case we cannot specialize the nested operations. |
| 219 | */ |
| 220 | const struct lttng_event_field *field; |
| 221 | }; |
| 222 | |
| 223 | struct estack_entry { |
| 224 | enum entry_type type; /* For dynamic typing. */ |
| 225 | union { |
| 226 | int64_t v; |
| 227 | double d; |
| 228 | |
| 229 | struct { |
| 230 | const char *str; |
| 231 | size_t seq_len; |
| 232 | enum estack_string_literal_type literal_type; |
| 233 | } s; |
| 234 | struct load_ptr ptr; |
| 235 | } u; |
| 236 | }; |
| 237 | |
| 238 | struct estack { |
| 239 | int top; /* top of stack */ |
| 240 | struct estack_entry e[FILTER_STACK_LEN]; |
| 241 | }; |
| 242 | |
| 243 | /* |
| 244 | * Always use aliased type for ax/bx (top of stack). |
| 245 | * When ax/bx are S64, use aliased value. |
| 246 | */ |
| 247 | #define estack_ax_v ax |
| 248 | #define estack_bx_v bx |
| 249 | #define estack_ax_t ax_t |
| 250 | #define estack_bx_t bx_t |
| 251 | |
| 252 | /* |
| 253 | * ax and bx registers can hold either integer, double or string. |
| 254 | */ |
| 255 | #define estack_ax(stack, top) \ |
| 256 | ({ \ |
| 257 | assert((top) > FILTER_STACK_EMPTY); \ |
| 258 | &(stack)->e[top]; \ |
| 259 | }) |
| 260 | |
| 261 | #define estack_bx(stack, top) \ |
| 262 | ({ \ |
| 263 | assert((top) > FILTER_STACK_EMPTY + 1); \ |
| 264 | &(stack)->e[(top) - 1]; \ |
| 265 | }) |
| 266 | |
| 267 | /* |
| 268 | * Currently, only integers (REG_S64) can be pushed into the stack. |
| 269 | */ |
| 270 | #define estack_push(stack, top, ax, bx, ax_t, bx_t) \ |
| 271 | do { \ |
| 272 | assert((top) < FILTER_STACK_LEN - 1); \ |
| 273 | (stack)->e[(top) - 1].u.v = (bx); \ |
| 274 | (stack)->e[(top) - 1].type = (bx_t); \ |
| 275 | (bx) = (ax); \ |
| 276 | (bx_t) = (ax_t); \ |
| 277 | ++(top); \ |
| 278 | } while (0) |
| 279 | |
| 280 | #define estack_pop(stack, top, ax, bx, ax_t, bx_t) \ |
| 281 | do { \ |
| 282 | assert((top) > FILTER_STACK_EMPTY); \ |
| 283 | (ax) = (bx); \ |
| 284 | (ax_t) = (bx_t); \ |
| 285 | (bx) = (stack)->e[(top) - 2].u.v; \ |
| 286 | (bx_t) = (stack)->e[(top) - 2].type; \ |
| 287 | (top)--; \ |
| 288 | } while (0) |
| 289 | |
| 290 | const char *print_op(enum filter_op op); |
| 291 | |
| 292 | int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode); |
| 293 | int lttng_filter_specialize_bytecode(struct lttng_event *event, |
| 294 | struct bytecode_runtime *bytecode); |
| 295 | |
| 296 | uint64_t lttng_filter_false(void *filter_data, |
| 297 | const char *filter_stack_data); |
| 298 | uint64_t lttng_filter_interpret_bytecode(void *filter_data, |
| 299 | const char *filter_stack_data); |
| 300 | |
| 301 | #endif /* _LTTNG_FILTER_H */ |