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953192ba MD |
1 | /* |
2 | * filter-visitor-generate-bytecode.c | |
3 | * | |
4 | * LTTng filter bytecode generation | |
5 | * | |
6 | * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
7 | * | |
8 | * This library is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU Lesser General Public License, version 2.1 only, | |
10 | * as published by the Free Software Foundation. | |
11 | * | |
12 | * This library is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public License | |
18 | * along with this library; if not, write to the Free Software Foundation, | |
19 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
24 | #include <errno.h> | |
46820c8b | 25 | #include <common/align.h> |
afc5df03 | 26 | #include <common/compat/string.h> |
46820c8b | 27 | |
953192ba MD |
28 | #include "filter-bytecode.h" |
29 | #include "filter-ir.h" | |
30 | #include "filter-ast.h" | |
31 | ||
a187da1a DG |
32 | #include <common/macros.h> |
33 | ||
953192ba MD |
34 | #ifndef max_t |
35 | #define max_t(type, a, b) ((type) ((a) > (b) ? (a) : (b))) | |
36 | #endif | |
37 | ||
953192ba MD |
38 | #define INIT_ALLOC_SIZE 4 |
39 | ||
40 | static | |
41 | int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx, | |
42 | struct ir_op *node); | |
43 | ||
01a204f0 CB |
44 | static inline int get_count_order(unsigned int count) |
45 | { | |
46 | int order; | |
47 | ||
afc5df03 | 48 | order = lttng_fls(count) - 1; |
01a204f0 CB |
49 | if (count & (count - 1)) |
50 | order++; | |
51 | return order; | |
52 | } | |
53 | ||
953192ba | 54 | static |
53a80697 | 55 | int bytecode_init(struct lttng_filter_bytecode_alloc **fb) |
953192ba | 56 | { |
1029587a MD |
57 | uint32_t alloc_len; |
58 | ||
59 | alloc_len = sizeof(struct lttng_filter_bytecode_alloc) + INIT_ALLOC_SIZE; | |
60 | *fb = calloc(alloc_len, 1); | |
953192ba MD |
61 | if (!*fb) { |
62 | return -ENOMEM; | |
63 | } else { | |
1029587a | 64 | (*fb)->alloc_len = alloc_len; |
953192ba MD |
65 | return 0; |
66 | } | |
67 | } | |
68 | ||
69 | static | |
53a80697 | 70 | int32_t bytecode_reserve(struct lttng_filter_bytecode_alloc **fb, uint32_t align, uint32_t len) |
953192ba MD |
71 | { |
72 | int32_t ret; | |
73 | uint32_t padding = offset_align((*fb)->b.len, align); | |
ec96a8f6 | 74 | uint32_t new_len = (*fb)->b.len + padding + len; |
1029587a | 75 | uint32_t new_alloc_len = sizeof(struct lttng_filter_bytecode_alloc) + new_len; |
ec96a8f6 | 76 | uint32_t old_alloc_len = (*fb)->alloc_len; |
953192ba | 77 | |
ec96a8f6 | 78 | if (new_len > LTTNG_FILTER_MAX_LEN) |
5ddb0a08 CB |
79 | return -EINVAL; |
80 | ||
ec96a8f6 | 81 | if (new_alloc_len > old_alloc_len) { |
d0b96690 DG |
82 | struct lttng_filter_bytecode_alloc *newptr; |
83 | ||
ec96a8f6 MD |
84 | new_alloc_len = |
85 | max_t(uint32_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1); | |
d0b96690 DG |
86 | newptr = realloc(*fb, new_alloc_len); |
87 | if (!newptr) | |
953192ba | 88 | return -ENOMEM; |
d0b96690 | 89 | *fb = newptr; |
1029587a | 90 | /* We zero directly the memory from start of allocation. */ |
ec96a8f6 MD |
91 | memset(&((char *) *fb)[old_alloc_len], 0, new_alloc_len - old_alloc_len); |
92 | (*fb)->alloc_len = new_alloc_len; | |
953192ba MD |
93 | } |
94 | (*fb)->b.len += padding; | |
95 | ret = (*fb)->b.len; | |
96 | (*fb)->b.len += len; | |
97 | return ret; | |
98 | } | |
99 | ||
100 | static | |
53a80697 | 101 | int bytecode_push(struct lttng_filter_bytecode_alloc **fb, const void *data, |
953192ba MD |
102 | uint32_t align, uint32_t len) |
103 | { | |
104 | int32_t offset; | |
105 | ||
106 | offset = bytecode_reserve(fb, align, len); | |
107 | if (offset < 0) | |
108 | return offset; | |
109 | memcpy(&(*fb)->b.data[offset], data, len); | |
110 | return 0; | |
111 | } | |
112 | ||
113 | static | |
53a80697 | 114 | int bytecode_push_logical(struct lttng_filter_bytecode_alloc **fb, |
953192ba MD |
115 | struct logical_op *data, |
116 | uint32_t align, uint32_t len, | |
117 | uint16_t *skip_offset) | |
118 | { | |
119 | int32_t offset; | |
120 | ||
121 | offset = bytecode_reserve(fb, align, len); | |
122 | if (offset < 0) | |
123 | return offset; | |
124 | memcpy(&(*fb)->b.data[offset], data, len); | |
125 | *skip_offset = | |
126 | (void *) &((struct logical_op *) &(*fb)->b.data[offset])->skip_offset | |
127 | - (void *) &(*fb)->b.data[0]; | |
128 | return 0; | |
129 | } | |
130 | ||
131 | static | |
53a80697 | 132 | int bytecode_patch(struct lttng_filter_bytecode_alloc **fb, |
953192ba MD |
133 | const void *data, |
134 | uint16_t offset, | |
135 | uint32_t len) | |
136 | { | |
137 | if (offset >= (*fb)->b.len) { | |
138 | return -EINVAL; | |
139 | } | |
140 | memcpy(&(*fb)->b.data[offset], data, len); | |
141 | return 0; | |
142 | } | |
143 | ||
144 | static | |
145 | int visit_node_root(struct filter_parser_ctx *ctx, struct ir_op *node) | |
146 | { | |
147 | int ret; | |
148 | struct return_op insn; | |
149 | ||
150 | /* Visit child */ | |
151 | ret = recursive_visit_gen_bytecode(ctx, node->u.root.child); | |
152 | if (ret) | |
153 | return ret; | |
154 | ||
155 | /* Generate end of bytecode instruction */ | |
156 | insn.op = FILTER_OP_RETURN; | |
157 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); | |
158 | } | |
159 | ||
953192ba MD |
160 | static |
161 | int visit_node_load(struct filter_parser_ctx *ctx, struct ir_op *node) | |
162 | { | |
163 | int ret; | |
164 | ||
165 | switch (node->data_type) { | |
166 | case IR_DATA_UNKNOWN: | |
167 | default: | |
168 | fprintf(stderr, "[error] Unknown data type in %s\n", | |
169 | __func__); | |
170 | return -EINVAL; | |
171 | ||
172 | case IR_DATA_STRING: | |
173 | { | |
174 | struct load_op *insn; | |
175 | uint32_t insn_len = sizeof(struct load_op) | |
176 | + strlen(node->u.load.u.string) + 1; | |
177 | ||
178 | insn = calloc(insn_len, 1); | |
179 | if (!insn) | |
180 | return -ENOMEM; | |
181 | insn->op = FILTER_OP_LOAD_STRING; | |
953192ba MD |
182 | strcpy(insn->data, node->u.load.u.string); |
183 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); | |
184 | free(insn); | |
185 | return ret; | |
186 | } | |
187 | case IR_DATA_NUMERIC: | |
188 | { | |
189 | struct load_op *insn; | |
190 | uint32_t insn_len = sizeof(struct load_op) | |
191 | + sizeof(struct literal_numeric); | |
192 | ||
193 | insn = calloc(insn_len, 1); | |
194 | if (!insn) | |
195 | return -ENOMEM; | |
196 | insn->op = FILTER_OP_LOAD_S64; | |
58d494e4 | 197 | memcpy(insn->data, &node->u.load.u.num, sizeof(int64_t)); |
953192ba MD |
198 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
199 | free(insn); | |
200 | return ret; | |
201 | } | |
e90d8561 MD |
202 | case IR_DATA_FLOAT: |
203 | { | |
204 | struct load_op *insn; | |
205 | uint32_t insn_len = sizeof(struct load_op) | |
206 | + sizeof(struct literal_double); | |
207 | ||
208 | insn = calloc(insn_len, 1); | |
209 | if (!insn) | |
210 | return -ENOMEM; | |
211 | insn->op = FILTER_OP_LOAD_DOUBLE; | |
58d494e4 | 212 | memcpy(insn->data, &node->u.load.u.flt, sizeof(double)); |
e90d8561 MD |
213 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
214 | free(insn); | |
215 | return ret; | |
216 | } | |
586dc72f MD |
217 | case IR_DATA_FIELD_REF: /* fall-through */ |
218 | case IR_DATA_GET_CONTEXT_REF: | |
953192ba MD |
219 | { |
220 | struct load_op *insn; | |
221 | uint32_t insn_len = sizeof(struct load_op) | |
222 | + sizeof(struct field_ref); | |
223 | struct field_ref ref_offset; | |
ec96a8f6 MD |
224 | uint32_t reloc_offset_u32; |
225 | uint16_t reloc_offset; | |
953192ba MD |
226 | |
227 | insn = calloc(insn_len, 1); | |
228 | if (!insn) | |
229 | return -ENOMEM; | |
586dc72f MD |
230 | switch(node->data_type) { |
231 | case IR_DATA_FIELD_REF: | |
232 | insn->op = FILTER_OP_LOAD_FIELD_REF; | |
233 | break; | |
234 | case IR_DATA_GET_CONTEXT_REF: | |
235 | insn->op = FILTER_OP_GET_CONTEXT_REF; | |
236 | break; | |
237 | default: | |
3a68137c | 238 | free(insn); |
586dc72f MD |
239 | return -EINVAL; |
240 | } | |
953192ba MD |
241 | ref_offset.offset = (uint16_t) -1U; |
242 | memcpy(insn->data, &ref_offset, sizeof(ref_offset)); | |
65775683 | 243 | /* reloc_offset points to struct load_op */ |
ec96a8f6 MD |
244 | reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b); |
245 | if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) { | |
246 | free(insn); | |
247 | return -EINVAL; | |
248 | } | |
249 | reloc_offset = (uint16_t) reloc_offset_u32; | |
953192ba MD |
250 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
251 | if (ret) { | |
252 | free(insn); | |
253 | return ret; | |
254 | } | |
255 | /* append reloc */ | |
256 | ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset, | |
257 | 1, sizeof(reloc_offset)); | |
258 | if (ret) { | |
259 | free(insn); | |
260 | return ret; | |
261 | } | |
262 | ret = bytecode_push(&ctx->bytecode_reloc, node->u.load.u.ref, | |
263 | 1, strlen(node->u.load.u.ref) + 1); | |
264 | free(insn); | |
265 | return ret; | |
266 | } | |
267 | } | |
268 | } | |
269 | ||
270 | static | |
271 | int visit_node_unary(struct filter_parser_ctx *ctx, struct ir_op *node) | |
272 | { | |
273 | int ret; | |
274 | struct unary_op insn; | |
275 | ||
276 | /* Visit child */ | |
277 | ret = recursive_visit_gen_bytecode(ctx, node->u.unary.child); | |
278 | if (ret) | |
279 | return ret; | |
280 | ||
281 | /* Generate end of bytecode instruction */ | |
282 | switch (node->u.unary.type) { | |
283 | case AST_UNARY_UNKNOWN: | |
284 | default: | |
285 | fprintf(stderr, "[error] Unknown unary node type in %s\n", | |
286 | __func__); | |
287 | return -EINVAL; | |
288 | case AST_UNARY_PLUS: | |
289 | /* Nothing to do. */ | |
290 | return 0; | |
291 | case AST_UNARY_MINUS: | |
292 | insn.op = FILTER_OP_UNARY_MINUS; | |
953192ba MD |
293 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); |
294 | case AST_UNARY_NOT: | |
295 | insn.op = FILTER_OP_UNARY_NOT; | |
953192ba MD |
296 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); |
297 | } | |
298 | } | |
299 | ||
300 | /* | |
301 | * Binary comparator nesting is disallowed. This allows fitting into | |
302 | * only 2 registers. | |
303 | */ | |
304 | static | |
305 | int visit_node_binary(struct filter_parser_ctx *ctx, struct ir_op *node) | |
306 | { | |
307 | int ret; | |
308 | struct binary_op insn; | |
309 | ||
310 | /* Visit child */ | |
311 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left); | |
312 | if (ret) | |
313 | return ret; | |
314 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right); | |
315 | if (ret) | |
316 | return ret; | |
317 | ||
318 | switch (node->u.binary.type) { | |
319 | case AST_OP_UNKNOWN: | |
320 | default: | |
321 | fprintf(stderr, "[error] Unknown unary node type in %s\n", | |
322 | __func__); | |
323 | return -EINVAL; | |
324 | ||
325 | case AST_OP_AND: | |
326 | case AST_OP_OR: | |
327 | fprintf(stderr, "[error] Unexpected logical node type in %s\n", | |
328 | __func__); | |
329 | return -EINVAL; | |
330 | ||
331 | case AST_OP_MUL: | |
332 | insn.op = FILTER_OP_MUL; | |
333 | break; | |
334 | case AST_OP_DIV: | |
335 | insn.op = FILTER_OP_DIV; | |
336 | break; | |
337 | case AST_OP_MOD: | |
338 | insn.op = FILTER_OP_MOD; | |
339 | break; | |
340 | case AST_OP_PLUS: | |
341 | insn.op = FILTER_OP_PLUS; | |
342 | break; | |
343 | case AST_OP_MINUS: | |
344 | insn.op = FILTER_OP_MINUS; | |
345 | break; | |
346 | case AST_OP_RSHIFT: | |
347 | insn.op = FILTER_OP_RSHIFT; | |
348 | break; | |
349 | case AST_OP_LSHIFT: | |
350 | insn.op = FILTER_OP_LSHIFT; | |
351 | break; | |
352 | case AST_OP_BIN_AND: | |
353 | insn.op = FILTER_OP_BIN_AND; | |
354 | break; | |
355 | case AST_OP_BIN_OR: | |
356 | insn.op = FILTER_OP_BIN_OR; | |
357 | break; | |
358 | case AST_OP_BIN_XOR: | |
359 | insn.op = FILTER_OP_BIN_XOR; | |
360 | break; | |
361 | ||
362 | case AST_OP_EQ: | |
363 | insn.op = FILTER_OP_EQ; | |
364 | break; | |
365 | case AST_OP_NE: | |
366 | insn.op = FILTER_OP_NE; | |
367 | break; | |
368 | case AST_OP_GT: | |
369 | insn.op = FILTER_OP_GT; | |
370 | break; | |
371 | case AST_OP_LT: | |
372 | insn.op = FILTER_OP_LT; | |
373 | break; | |
374 | case AST_OP_GE: | |
375 | insn.op = FILTER_OP_GE; | |
376 | break; | |
377 | case AST_OP_LE: | |
378 | insn.op = FILTER_OP_LE; | |
379 | break; | |
380 | } | |
381 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); | |
382 | } | |
383 | ||
8cf9540a MD |
384 | /* |
385 | * A logical op always return a s64 (1 or 0). | |
386 | */ | |
953192ba MD |
387 | static |
388 | int visit_node_logical(struct filter_parser_ctx *ctx, struct ir_op *node) | |
389 | { | |
390 | int ret; | |
391 | struct logical_op insn; | |
392 | uint16_t skip_offset_loc; | |
393 | uint16_t target_loc; | |
394 | ||
395 | /* Visit left child */ | |
396 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left); | |
397 | if (ret) | |
398 | return ret; | |
8cf9540a | 399 | /* Cast to s64 if float or field ref */ |
586dc72f MD |
400 | if ((node->u.binary.left->data_type == IR_DATA_FIELD_REF |
401 | || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF) | |
8cf9540a MD |
402 | || node->u.binary.left->data_type == IR_DATA_FLOAT) { |
403 | struct cast_op cast_insn; | |
404 | ||
586dc72f MD |
405 | if (node->u.binary.left->data_type == IR_DATA_FIELD_REF |
406 | || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF) { | |
29fefef8 MD |
407 | cast_insn.op = FILTER_OP_CAST_TO_S64; |
408 | } else { | |
409 | cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64; | |
410 | } | |
8cf9540a MD |
411 | ret = bytecode_push(&ctx->bytecode, &cast_insn, |
412 | 1, sizeof(cast_insn)); | |
413 | if (ret) | |
414 | return ret; | |
415 | } | |
953192ba MD |
416 | switch (node->u.logical.type) { |
417 | default: | |
418 | fprintf(stderr, "[error] Unknown node type in %s\n", | |
419 | __func__); | |
420 | return -EINVAL; | |
421 | ||
422 | case AST_OP_AND: | |
423 | insn.op = FILTER_OP_AND; | |
424 | break; | |
425 | case AST_OP_OR: | |
426 | insn.op = FILTER_OP_OR; | |
427 | break; | |
428 | } | |
429 | insn.skip_offset = (uint16_t) -1UL; /* Temporary */ | |
430 | ret = bytecode_push_logical(&ctx->bytecode, &insn, 1, sizeof(insn), | |
431 | &skip_offset_loc); | |
432 | if (ret) | |
433 | return ret; | |
434 | /* Visit right child */ | |
435 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right); | |
436 | if (ret) | |
437 | return ret; | |
8cf9540a | 438 | /* Cast to s64 if float or field ref */ |
586dc72f MD |
439 | if ((node->u.binary.right->data_type == IR_DATA_FIELD_REF |
440 | || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF) | |
8cf9540a MD |
441 | || node->u.binary.right->data_type == IR_DATA_FLOAT) { |
442 | struct cast_op cast_insn; | |
443 | ||
586dc72f MD |
444 | if (node->u.binary.right->data_type == IR_DATA_FIELD_REF |
445 | || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF) { | |
29fefef8 MD |
446 | cast_insn.op = FILTER_OP_CAST_TO_S64; |
447 | } else { | |
448 | cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64; | |
449 | } | |
8cf9540a MD |
450 | ret = bytecode_push(&ctx->bytecode, &cast_insn, |
451 | 1, sizeof(cast_insn)); | |
452 | if (ret) | |
453 | return ret; | |
454 | } | |
953192ba MD |
455 | /* We now know where the logical op can skip. */ |
456 | target_loc = (uint16_t) bytecode_get_len(&ctx->bytecode->b); | |
457 | ret = bytecode_patch(&ctx->bytecode, | |
458 | &target_loc, /* Offset to jump to */ | |
459 | skip_offset_loc, /* Where to patch */ | |
460 | sizeof(uint16_t)); | |
461 | return ret; | |
462 | } | |
463 | ||
464 | /* | |
465 | * Postorder traversal of the tree. We need the children result before | |
466 | * we can evaluate the parent. | |
467 | */ | |
468 | static | |
469 | int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx, | |
470 | struct ir_op *node) | |
471 | { | |
472 | switch (node->op) { | |
473 | case IR_OP_UNKNOWN: | |
474 | default: | |
475 | fprintf(stderr, "[error] Unknown node type in %s\n", | |
476 | __func__); | |
477 | return -EINVAL; | |
478 | ||
479 | case IR_OP_ROOT: | |
480 | return visit_node_root(ctx, node); | |
481 | case IR_OP_LOAD: | |
482 | return visit_node_load(ctx, node); | |
483 | case IR_OP_UNARY: | |
484 | return visit_node_unary(ctx, node); | |
485 | case IR_OP_BINARY: | |
486 | return visit_node_binary(ctx, node); | |
487 | case IR_OP_LOGICAL: | |
488 | return visit_node_logical(ctx, node); | |
489 | } | |
490 | } | |
491 | ||
a187da1a | 492 | LTTNG_HIDDEN |
953192ba MD |
493 | void filter_bytecode_free(struct filter_parser_ctx *ctx) |
494 | { | |
7ca1dc6f DG |
495 | if (!ctx) { |
496 | return; | |
497 | } | |
498 | ||
3f0c8837 DG |
499 | if (ctx->bytecode) { |
500 | free(ctx->bytecode); | |
501 | ctx->bytecode = NULL; | |
502 | } | |
503 | ||
504 | if (ctx->bytecode_reloc) { | |
505 | free(ctx->bytecode_reloc); | |
506 | ctx->bytecode_reloc = NULL; | |
507 | } | |
953192ba MD |
508 | } |
509 | ||
a187da1a | 510 | LTTNG_HIDDEN |
953192ba MD |
511 | int filter_visitor_bytecode_generate(struct filter_parser_ctx *ctx) |
512 | { | |
513 | int ret; | |
514 | ||
515 | ret = bytecode_init(&ctx->bytecode); | |
516 | if (ret) | |
517 | return ret; | |
518 | ret = bytecode_init(&ctx->bytecode_reloc); | |
519 | if (ret) | |
520 | goto error; | |
521 | ret = recursive_visit_gen_bytecode(ctx, ctx->ir_root); | |
522 | if (ret) | |
523 | goto error; | |
524 | ||
525 | /* Finally, append symbol table to bytecode */ | |
526 | ctx->bytecode->b.reloc_table_offset = bytecode_get_len(&ctx->bytecode->b); | |
527 | return bytecode_push(&ctx->bytecode, ctx->bytecode_reloc->b.data, | |
528 | 1, bytecode_get_len(&ctx->bytecode_reloc->b)); | |
529 | ||
530 | error: | |
531 | filter_bytecode_free(ctx); | |
532 | return ret; | |
533 | } |