Commit | Line | Data |
---|---|---|
07dfc1d0 MD |
1 | /* |
2 | * lttng-filter-validator.c | |
3 | * | |
4 | * LTTng modules filter bytecode validator. | |
5 | * | |
6 | * Copyright (C) 2010-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; only | |
11 | * version 2.1 of the License. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
21 | */ | |
22 | ||
499cc3f7 | 23 | #include <linux/types.h> |
07dfc1d0 MD |
24 | #include <linux/jhash.h> |
25 | #include <linux/slab.h> | |
26 | ||
241ae9a8 MD |
27 | #include <wrapper/list.h> |
28 | #include <lttng-filter.h> | |
07dfc1d0 MD |
29 | |
30 | #define MERGE_POINT_TABLE_BITS 7 | |
31 | #define MERGE_POINT_TABLE_SIZE (1U << MERGE_POINT_TABLE_BITS) | |
32 | ||
33 | /* merge point table node */ | |
34 | struct mp_node { | |
35 | struct hlist_node node; | |
36 | ||
37 | /* Context at merge point */ | |
38 | struct vstack stack; | |
39 | unsigned long target_pc; | |
40 | }; | |
41 | ||
42 | struct mp_table { | |
43 | struct hlist_head mp_head[MERGE_POINT_TABLE_SIZE]; | |
44 | }; | |
45 | ||
46 | static | |
47 | int lttng_hash_match(struct mp_node *mp_node, unsigned long key_pc) | |
48 | { | |
49 | if (mp_node->target_pc == key_pc) | |
50 | return 1; | |
51 | else | |
52 | return 0; | |
53 | } | |
54 | ||
55 | static | |
56 | int merge_points_compare(const struct vstack *stacka, | |
57 | const struct vstack *stackb) | |
58 | { | |
59 | int i, len; | |
60 | ||
61 | if (stacka->top != stackb->top) | |
62 | return 1; | |
63 | len = stacka->top + 1; | |
64 | WARN_ON_ONCE(len < 0); | |
65 | for (i = 0; i < len; i++) { | |
66 | if (stacka->e[i].type != stackb->e[i].type) | |
67 | return 1; | |
68 | } | |
69 | return 0; | |
70 | } | |
71 | ||
72 | static | |
73 | int merge_point_add_check(struct mp_table *mp_table, unsigned long target_pc, | |
74 | const struct vstack *stack) | |
75 | { | |
76 | struct mp_node *mp_node; | |
77 | unsigned long hash = jhash_1word(target_pc, 0); | |
78 | struct hlist_head *head; | |
79 | struct mp_node *lookup_node; | |
80 | int found = 0; | |
81 | ||
82 | dbg_printk("Filter: adding merge point at offset %lu, hash %lu\n", | |
83 | target_pc, hash); | |
84 | mp_node = kzalloc(sizeof(struct mp_node), GFP_KERNEL); | |
85 | if (!mp_node) | |
86 | return -ENOMEM; | |
87 | mp_node->target_pc = target_pc; | |
88 | memcpy(&mp_node->stack, stack, sizeof(mp_node->stack)); | |
89 | ||
90 | head = &mp_table->mp_head[hash & (MERGE_POINT_TABLE_SIZE - 1)]; | |
d216ecae | 91 | lttng_hlist_for_each_entry(lookup_node, head, node) { |
07dfc1d0 MD |
92 | if (lttng_hash_match(lookup_node, target_pc)) { |
93 | found = 1; | |
94 | break; | |
95 | } | |
96 | } | |
97 | if (found) { | |
98 | /* Key already present */ | |
99 | dbg_printk("Filter: compare merge points for offset %lu, hash %lu\n", | |
100 | target_pc, hash); | |
101 | kfree(mp_node); | |
102 | if (merge_points_compare(stack, &lookup_node->stack)) { | |
103 | printk(KERN_WARNING "Merge points differ for offset %lu\n", | |
104 | target_pc); | |
105 | return -EINVAL; | |
106 | } | |
5e13eb3c MD |
107 | } else { |
108 | hlist_add_head(&mp_node->node, head); | |
07dfc1d0 | 109 | } |
07dfc1d0 MD |
110 | return 0; |
111 | } | |
112 | ||
113 | /* | |
114 | * Binary comparators use top of stack and top of stack -1. | |
115 | */ | |
116 | static | |
117 | int bin_op_compare_check(struct vstack *stack, const char *str) | |
118 | { | |
119 | if (unlikely(!vstack_ax(stack) || !vstack_bx(stack))) | |
120 | goto error_unknown; | |
121 | ||
122 | switch (vstack_ax(stack)->type) { | |
123 | default: | |
124 | case REG_DOUBLE: | |
125 | goto error_unknown; | |
126 | ||
127 | case REG_STRING: | |
128 | switch (vstack_bx(stack)->type) { | |
129 | default: | |
130 | case REG_DOUBLE: | |
131 | goto error_unknown; | |
132 | ||
133 | case REG_STRING: | |
134 | break; | |
135 | case REG_S64: | |
136 | goto error_mismatch; | |
137 | } | |
138 | break; | |
139 | case REG_S64: | |
140 | switch (vstack_bx(stack)->type) { | |
141 | default: | |
142 | case REG_DOUBLE: | |
143 | goto error_unknown; | |
144 | ||
145 | case REG_STRING: | |
146 | goto error_mismatch; | |
147 | ||
148 | case REG_S64: | |
149 | break; | |
150 | } | |
151 | break; | |
152 | } | |
153 | return 0; | |
154 | ||
155 | error_unknown: | |
156 | return -EINVAL; | |
157 | ||
158 | error_mismatch: | |
159 | printk(KERN_WARNING "type mismatch for '%s' binary operator\n", str); | |
160 | return -EINVAL; | |
161 | } | |
162 | ||
163 | /* | |
164 | * Validate bytecode range overflow within the validation pass. | |
165 | * Called for each instruction encountered. | |
166 | */ | |
167 | static | |
168 | int bytecode_validate_overflow(struct bytecode_runtime *bytecode, | |
169 | void *start_pc, void *pc) | |
170 | { | |
171 | int ret = 0; | |
172 | ||
173 | switch (*(filter_opcode_t *) pc) { | |
174 | case FILTER_OP_UNKNOWN: | |
175 | default: | |
176 | { | |
177 | printk(KERN_WARNING "unknown bytecode op %u\n", | |
178 | (unsigned int) *(filter_opcode_t *) pc); | |
179 | ret = -EINVAL; | |
180 | break; | |
181 | } | |
182 | ||
183 | case FILTER_OP_RETURN: | |
184 | { | |
185 | if (unlikely(pc + sizeof(struct return_op) | |
186 | > start_pc + bytecode->len)) { | |
187 | ret = -ERANGE; | |
188 | } | |
189 | break; | |
190 | } | |
191 | ||
192 | /* binary */ | |
193 | case FILTER_OP_MUL: | |
194 | case FILTER_OP_DIV: | |
195 | case FILTER_OP_MOD: | |
196 | case FILTER_OP_PLUS: | |
197 | case FILTER_OP_MINUS: | |
198 | case FILTER_OP_RSHIFT: | |
199 | case FILTER_OP_LSHIFT: | |
200 | case FILTER_OP_BIN_AND: | |
201 | case FILTER_OP_BIN_OR: | |
202 | case FILTER_OP_BIN_XOR: | |
203 | case FILTER_OP_EQ_DOUBLE: | |
204 | case FILTER_OP_NE_DOUBLE: | |
205 | case FILTER_OP_GT_DOUBLE: | |
206 | case FILTER_OP_LT_DOUBLE: | |
207 | case FILTER_OP_GE_DOUBLE: | |
208 | case FILTER_OP_LE_DOUBLE: | |
209 | /* Floating point */ | |
210 | case FILTER_OP_EQ_DOUBLE_S64: | |
211 | case FILTER_OP_NE_DOUBLE_S64: | |
212 | case FILTER_OP_GT_DOUBLE_S64: | |
213 | case FILTER_OP_LT_DOUBLE_S64: | |
214 | case FILTER_OP_GE_DOUBLE_S64: | |
215 | case FILTER_OP_LE_DOUBLE_S64: | |
216 | case FILTER_OP_EQ_S64_DOUBLE: | |
217 | case FILTER_OP_NE_S64_DOUBLE: | |
218 | case FILTER_OP_GT_S64_DOUBLE: | |
219 | case FILTER_OP_LT_S64_DOUBLE: | |
220 | case FILTER_OP_GE_S64_DOUBLE: | |
221 | case FILTER_OP_LE_S64_DOUBLE: | |
222 | case FILTER_OP_LOAD_FIELD_REF_DOUBLE: | |
223 | case FILTER_OP_GET_CONTEXT_REF_DOUBLE: | |
224 | case FILTER_OP_LOAD_DOUBLE: | |
225 | case FILTER_OP_CAST_DOUBLE_TO_S64: | |
226 | case FILTER_OP_UNARY_PLUS_DOUBLE: | |
227 | case FILTER_OP_UNARY_MINUS_DOUBLE: | |
228 | case FILTER_OP_UNARY_NOT_DOUBLE: | |
229 | { | |
230 | printk(KERN_WARNING "unsupported bytecode op %u\n", | |
231 | (unsigned int) *(filter_opcode_t *) pc); | |
232 | ret = -EINVAL; | |
233 | break; | |
234 | } | |
235 | ||
236 | case FILTER_OP_EQ: | |
237 | case FILTER_OP_NE: | |
238 | case FILTER_OP_GT: | |
239 | case FILTER_OP_LT: | |
240 | case FILTER_OP_GE: | |
241 | case FILTER_OP_LE: | |
242 | case FILTER_OP_EQ_STRING: | |
243 | case FILTER_OP_NE_STRING: | |
244 | case FILTER_OP_GT_STRING: | |
245 | case FILTER_OP_LT_STRING: | |
246 | case FILTER_OP_GE_STRING: | |
247 | case FILTER_OP_LE_STRING: | |
248 | case FILTER_OP_EQ_S64: | |
249 | case FILTER_OP_NE_S64: | |
250 | case FILTER_OP_GT_S64: | |
251 | case FILTER_OP_LT_S64: | |
252 | case FILTER_OP_GE_S64: | |
253 | case FILTER_OP_LE_S64: | |
254 | { | |
255 | if (unlikely(pc + sizeof(struct binary_op) | |
256 | > start_pc + bytecode->len)) { | |
257 | ret = -ERANGE; | |
258 | } | |
259 | break; | |
260 | } | |
261 | ||
262 | /* unary */ | |
263 | case FILTER_OP_UNARY_PLUS: | |
264 | case FILTER_OP_UNARY_MINUS: | |
265 | case FILTER_OP_UNARY_NOT: | |
266 | case FILTER_OP_UNARY_PLUS_S64: | |
267 | case FILTER_OP_UNARY_MINUS_S64: | |
268 | case FILTER_OP_UNARY_NOT_S64: | |
269 | { | |
270 | if (unlikely(pc + sizeof(struct unary_op) | |
271 | > start_pc + bytecode->len)) { | |
272 | ret = -ERANGE; | |
273 | } | |
274 | break; | |
275 | } | |
276 | ||
277 | /* logical */ | |
278 | case FILTER_OP_AND: | |
279 | case FILTER_OP_OR: | |
280 | { | |
281 | if (unlikely(pc + sizeof(struct logical_op) | |
282 | > start_pc + bytecode->len)) { | |
283 | ret = -ERANGE; | |
284 | } | |
285 | break; | |
286 | } | |
287 | ||
288 | /* load field ref */ | |
289 | case FILTER_OP_LOAD_FIELD_REF: | |
290 | { | |
291 | printk(KERN_WARNING "Unknown field ref type\n"); | |
292 | ret = -EINVAL; | |
293 | break; | |
294 | } | |
295 | /* get context ref */ | |
296 | case FILTER_OP_GET_CONTEXT_REF: | |
297 | { | |
298 | printk(KERN_WARNING "Unknown field ref type\n"); | |
299 | ret = -EINVAL; | |
300 | break; | |
301 | } | |
302 | case FILTER_OP_LOAD_FIELD_REF_STRING: | |
303 | case FILTER_OP_LOAD_FIELD_REF_SEQUENCE: | |
f127e61e MD |
304 | case FILTER_OP_LOAD_FIELD_REF_USER_STRING: |
305 | case FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE: | |
07dfc1d0 MD |
306 | case FILTER_OP_LOAD_FIELD_REF_S64: |
307 | case FILTER_OP_GET_CONTEXT_REF_STRING: | |
308 | case FILTER_OP_GET_CONTEXT_REF_S64: | |
309 | { | |
310 | if (unlikely(pc + sizeof(struct load_op) + sizeof(struct field_ref) | |
311 | > start_pc + bytecode->len)) { | |
312 | ret = -ERANGE; | |
313 | } | |
314 | break; | |
315 | } | |
316 | ||
317 | /* load from immediate operand */ | |
318 | case FILTER_OP_LOAD_STRING: | |
319 | { | |
320 | struct load_op *insn = (struct load_op *) pc; | |
321 | uint32_t str_len, maxlen; | |
322 | ||
323 | if (unlikely(pc + sizeof(struct load_op) | |
324 | > start_pc + bytecode->len)) { | |
325 | ret = -ERANGE; | |
326 | break; | |
327 | } | |
328 | ||
329 | maxlen = start_pc + bytecode->len - pc - sizeof(struct load_op); | |
330 | str_len = strnlen(insn->data, maxlen); | |
331 | if (unlikely(str_len >= maxlen)) { | |
332 | /* Final '\0' not found within range */ | |
333 | ret = -ERANGE; | |
334 | } | |
335 | break; | |
336 | } | |
337 | ||
338 | case FILTER_OP_LOAD_S64: | |
339 | { | |
340 | if (unlikely(pc + sizeof(struct load_op) + sizeof(struct literal_numeric) | |
341 | > start_pc + bytecode->len)) { | |
342 | ret = -ERANGE; | |
343 | } | |
344 | break; | |
345 | } | |
346 | ||
347 | case FILTER_OP_CAST_TO_S64: | |
348 | case FILTER_OP_CAST_NOP: | |
349 | { | |
350 | if (unlikely(pc + sizeof(struct cast_op) | |
351 | > start_pc + bytecode->len)) { | |
352 | ret = -ERANGE; | |
353 | } | |
354 | break; | |
355 | } | |
356 | ||
357 | } | |
358 | ||
359 | return ret; | |
360 | } | |
361 | ||
362 | static | |
363 | unsigned long delete_all_nodes(struct mp_table *mp_table) | |
364 | { | |
365 | struct mp_node *mp_node; | |
366 | struct hlist_node *tmp; | |
367 | unsigned long nr_nodes = 0; | |
368 | int i; | |
369 | ||
370 | for (i = 0; i < MERGE_POINT_TABLE_SIZE; i++) { | |
371 | struct hlist_head *head; | |
372 | ||
373 | head = &mp_table->mp_head[i]; | |
d216ecae | 374 | lttng_hlist_for_each_entry_safe(mp_node, tmp, head, node) { |
07dfc1d0 MD |
375 | kfree(mp_node); |
376 | nr_nodes++; | |
377 | } | |
378 | } | |
379 | return nr_nodes; | |
380 | } | |
381 | ||
382 | /* | |
383 | * Return value: | |
384 | * 0: success | |
385 | * <0: error | |
386 | */ | |
387 | static | |
388 | int validate_instruction_context(struct bytecode_runtime *bytecode, | |
389 | struct vstack *stack, | |
390 | void *start_pc, | |
391 | void *pc) | |
392 | { | |
393 | int ret = 0; | |
394 | ||
395 | switch (*(filter_opcode_t *) pc) { | |
396 | case FILTER_OP_UNKNOWN: | |
397 | default: | |
398 | { | |
399 | printk(KERN_WARNING "unknown bytecode op %u\n", | |
400 | (unsigned int) *(filter_opcode_t *) pc); | |
401 | ret = -EINVAL; | |
402 | goto end; | |
403 | } | |
404 | ||
405 | case FILTER_OP_RETURN: | |
406 | { | |
407 | goto end; | |
408 | } | |
409 | ||
410 | /* binary */ | |
411 | case FILTER_OP_MUL: | |
412 | case FILTER_OP_DIV: | |
413 | case FILTER_OP_MOD: | |
414 | case FILTER_OP_PLUS: | |
415 | case FILTER_OP_MINUS: | |
416 | case FILTER_OP_RSHIFT: | |
417 | case FILTER_OP_LSHIFT: | |
418 | case FILTER_OP_BIN_AND: | |
419 | case FILTER_OP_BIN_OR: | |
420 | case FILTER_OP_BIN_XOR: | |
421 | /* Floating point */ | |
422 | case FILTER_OP_EQ_DOUBLE: | |
423 | case FILTER_OP_NE_DOUBLE: | |
424 | case FILTER_OP_GT_DOUBLE: | |
425 | case FILTER_OP_LT_DOUBLE: | |
426 | case FILTER_OP_GE_DOUBLE: | |
427 | case FILTER_OP_LE_DOUBLE: | |
428 | case FILTER_OP_EQ_DOUBLE_S64: | |
429 | case FILTER_OP_NE_DOUBLE_S64: | |
430 | case FILTER_OP_GT_DOUBLE_S64: | |
431 | case FILTER_OP_LT_DOUBLE_S64: | |
432 | case FILTER_OP_GE_DOUBLE_S64: | |
433 | case FILTER_OP_LE_DOUBLE_S64: | |
434 | case FILTER_OP_EQ_S64_DOUBLE: | |
435 | case FILTER_OP_NE_S64_DOUBLE: | |
436 | case FILTER_OP_GT_S64_DOUBLE: | |
437 | case FILTER_OP_LT_S64_DOUBLE: | |
438 | case FILTER_OP_GE_S64_DOUBLE: | |
439 | case FILTER_OP_LE_S64_DOUBLE: | |
440 | case FILTER_OP_UNARY_PLUS_DOUBLE: | |
441 | case FILTER_OP_UNARY_MINUS_DOUBLE: | |
442 | case FILTER_OP_UNARY_NOT_DOUBLE: | |
443 | case FILTER_OP_LOAD_FIELD_REF_DOUBLE: | |
444 | case FILTER_OP_LOAD_DOUBLE: | |
445 | case FILTER_OP_CAST_DOUBLE_TO_S64: | |
446 | case FILTER_OP_GET_CONTEXT_REF_DOUBLE: | |
447 | { | |
448 | printk(KERN_WARNING "unsupported bytecode op %u\n", | |
449 | (unsigned int) *(filter_opcode_t *) pc); | |
450 | ret = -EINVAL; | |
451 | goto end; | |
452 | } | |
453 | ||
454 | case FILTER_OP_EQ: | |
455 | { | |
456 | ret = bin_op_compare_check(stack, "=="); | |
457 | if (ret) | |
458 | goto end; | |
459 | break; | |
460 | } | |
461 | case FILTER_OP_NE: | |
462 | { | |
463 | ret = bin_op_compare_check(stack, "!="); | |
464 | if (ret) | |
465 | goto end; | |
466 | break; | |
467 | } | |
468 | case FILTER_OP_GT: | |
469 | { | |
470 | ret = bin_op_compare_check(stack, ">"); | |
471 | if (ret) | |
472 | goto end; | |
473 | break; | |
474 | } | |
475 | case FILTER_OP_LT: | |
476 | { | |
477 | ret = bin_op_compare_check(stack, "<"); | |
478 | if (ret) | |
479 | goto end; | |
480 | break; | |
481 | } | |
482 | case FILTER_OP_GE: | |
483 | { | |
484 | ret = bin_op_compare_check(stack, ">="); | |
485 | if (ret) | |
486 | goto end; | |
487 | break; | |
488 | } | |
489 | case FILTER_OP_LE: | |
490 | { | |
491 | ret = bin_op_compare_check(stack, "<="); | |
492 | if (ret) | |
493 | goto end; | |
494 | break; | |
495 | } | |
496 | ||
497 | case FILTER_OP_EQ_STRING: | |
498 | case FILTER_OP_NE_STRING: | |
499 | case FILTER_OP_GT_STRING: | |
500 | case FILTER_OP_LT_STRING: | |
501 | case FILTER_OP_GE_STRING: | |
502 | case FILTER_OP_LE_STRING: | |
503 | { | |
504 | if (!vstack_ax(stack) || !vstack_bx(stack)) { | |
505 | printk(KERN_WARNING "Empty stack\n"); | |
506 | ret = -EINVAL; | |
507 | goto end; | |
508 | } | |
509 | if (vstack_ax(stack)->type != REG_STRING | |
510 | || vstack_bx(stack)->type != REG_STRING) { | |
511 | printk(KERN_WARNING "Unexpected register type for string comparator\n"); | |
512 | ret = -EINVAL; | |
513 | goto end; | |
514 | } | |
515 | break; | |
516 | } | |
517 | ||
518 | case FILTER_OP_EQ_S64: | |
519 | case FILTER_OP_NE_S64: | |
520 | case FILTER_OP_GT_S64: | |
521 | case FILTER_OP_LT_S64: | |
522 | case FILTER_OP_GE_S64: | |
523 | case FILTER_OP_LE_S64: | |
524 | { | |
525 | if (!vstack_ax(stack) || !vstack_bx(stack)) { | |
526 | printk(KERN_WARNING "Empty stack\n"); | |
527 | ret = -EINVAL; | |
528 | goto end; | |
529 | } | |
530 | if (vstack_ax(stack)->type != REG_S64 | |
531 | || vstack_bx(stack)->type != REG_S64) { | |
532 | printk(KERN_WARNING "Unexpected register type for s64 comparator\n"); | |
533 | ret = -EINVAL; | |
534 | goto end; | |
535 | } | |
536 | break; | |
537 | } | |
538 | ||
539 | /* unary */ | |
540 | case FILTER_OP_UNARY_PLUS: | |
541 | case FILTER_OP_UNARY_MINUS: | |
542 | case FILTER_OP_UNARY_NOT: | |
543 | { | |
544 | if (!vstack_ax(stack)) { | |
545 | printk(KERN_WARNING "Empty stack\n"); | |
546 | ret = -EINVAL; | |
547 | goto end; | |
548 | } | |
549 | switch (vstack_ax(stack)->type) { | |
550 | default: | |
551 | case REG_DOUBLE: | |
552 | printk(KERN_WARNING "unknown register type\n"); | |
553 | ret = -EINVAL; | |
554 | goto end; | |
555 | ||
556 | case REG_STRING: | |
557 | printk(KERN_WARNING "Unary op can only be applied to numeric or floating point registers\n"); | |
558 | ret = -EINVAL; | |
559 | goto end; | |
560 | case REG_S64: | |
561 | break; | |
562 | } | |
563 | break; | |
564 | } | |
565 | ||
566 | case FILTER_OP_UNARY_PLUS_S64: | |
567 | case FILTER_OP_UNARY_MINUS_S64: | |
568 | case FILTER_OP_UNARY_NOT_S64: | |
569 | { | |
570 | if (!vstack_ax(stack)) { | |
571 | printk(KERN_WARNING "Empty stack\n"); | |
572 | ret = -EINVAL; | |
573 | goto end; | |
574 | } | |
575 | if (vstack_ax(stack)->type != REG_S64) { | |
576 | printk(KERN_WARNING "Invalid register type\n"); | |
577 | ret = -EINVAL; | |
578 | goto end; | |
579 | } | |
580 | break; | |
581 | } | |
582 | ||
583 | /* logical */ | |
584 | case FILTER_OP_AND: | |
585 | case FILTER_OP_OR: | |
586 | { | |
587 | struct logical_op *insn = (struct logical_op *) pc; | |
588 | ||
589 | if (!vstack_ax(stack)) { | |
590 | printk(KERN_WARNING "Empty stack\n"); | |
591 | ret = -EINVAL; | |
592 | goto end; | |
593 | } | |
594 | if (vstack_ax(stack)->type != REG_S64) { | |
595 | printk(KERN_WARNING "Logical comparator expects S64 register\n"); | |
596 | ret = -EINVAL; | |
597 | goto end; | |
598 | } | |
599 | ||
600 | dbg_printk("Validate jumping to bytecode offset %u\n", | |
601 | (unsigned int) insn->skip_offset); | |
602 | if (unlikely(start_pc + insn->skip_offset <= pc)) { | |
603 | printk(KERN_WARNING "Loops are not allowed in bytecode\n"); | |
604 | ret = -EINVAL; | |
605 | goto end; | |
606 | } | |
607 | break; | |
608 | } | |
609 | ||
610 | /* load field ref */ | |
611 | case FILTER_OP_LOAD_FIELD_REF: | |
612 | { | |
613 | printk(KERN_WARNING "Unknown field ref type\n"); | |
614 | ret = -EINVAL; | |
615 | goto end; | |
616 | } | |
617 | case FILTER_OP_LOAD_FIELD_REF_STRING: | |
618 | case FILTER_OP_LOAD_FIELD_REF_SEQUENCE: | |
f127e61e MD |
619 | case FILTER_OP_LOAD_FIELD_REF_USER_STRING: |
620 | case FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE: | |
07dfc1d0 MD |
621 | { |
622 | struct load_op *insn = (struct load_op *) pc; | |
623 | struct field_ref *ref = (struct field_ref *) insn->data; | |
624 | ||
625 | dbg_printk("Validate load field ref offset %u type string\n", | |
626 | ref->offset); | |
627 | break; | |
628 | } | |
629 | case FILTER_OP_LOAD_FIELD_REF_S64: | |
630 | { | |
631 | struct load_op *insn = (struct load_op *) pc; | |
632 | struct field_ref *ref = (struct field_ref *) insn->data; | |
633 | ||
634 | dbg_printk("Validate load field ref offset %u type s64\n", | |
635 | ref->offset); | |
636 | break; | |
637 | } | |
638 | ||
639 | /* load from immediate operand */ | |
640 | case FILTER_OP_LOAD_STRING: | |
641 | { | |
642 | break; | |
643 | } | |
644 | ||
645 | case FILTER_OP_LOAD_S64: | |
646 | { | |
647 | break; | |
648 | } | |
649 | ||
650 | case FILTER_OP_CAST_TO_S64: | |
651 | { | |
652 | struct cast_op *insn = (struct cast_op *) pc; | |
653 | ||
654 | if (!vstack_ax(stack)) { | |
655 | printk(KERN_WARNING "Empty stack\n"); | |
656 | ret = -EINVAL; | |
657 | goto end; | |
658 | } | |
659 | switch (vstack_ax(stack)->type) { | |
660 | default: | |
661 | case REG_DOUBLE: | |
662 | printk(KERN_WARNING "unknown register type\n"); | |
663 | ret = -EINVAL; | |
664 | goto end; | |
665 | ||
666 | case REG_STRING: | |
667 | printk(KERN_WARNING "Cast op can only be applied to numeric or floating point registers\n"); | |
668 | ret = -EINVAL; | |
669 | goto end; | |
670 | case REG_S64: | |
671 | break; | |
672 | } | |
673 | if (insn->op == FILTER_OP_CAST_DOUBLE_TO_S64) { | |
674 | if (vstack_ax(stack)->type != REG_DOUBLE) { | |
675 | printk(KERN_WARNING "Cast expects double\n"); | |
676 | ret = -EINVAL; | |
677 | goto end; | |
678 | } | |
679 | } | |
680 | break; | |
681 | } | |
682 | case FILTER_OP_CAST_NOP: | |
683 | { | |
684 | break; | |
685 | } | |
686 | ||
687 | /* get context ref */ | |
688 | case FILTER_OP_GET_CONTEXT_REF: | |
689 | { | |
690 | printk(KERN_WARNING "Unknown get context ref type\n"); | |
691 | ret = -EINVAL; | |
692 | goto end; | |
693 | } | |
694 | case FILTER_OP_GET_CONTEXT_REF_STRING: | |
695 | { | |
696 | struct load_op *insn = (struct load_op *) pc; | |
697 | struct field_ref *ref = (struct field_ref *) insn->data; | |
698 | ||
699 | dbg_printk("Validate get context ref offset %u type string\n", | |
700 | ref->offset); | |
701 | break; | |
702 | } | |
703 | case FILTER_OP_GET_CONTEXT_REF_S64: | |
704 | { | |
705 | struct load_op *insn = (struct load_op *) pc; | |
706 | struct field_ref *ref = (struct field_ref *) insn->data; | |
707 | ||
708 | dbg_printk("Validate get context ref offset %u type s64\n", | |
709 | ref->offset); | |
710 | break; | |
711 | } | |
712 | ||
713 | } | |
714 | end: | |
715 | return ret; | |
716 | } | |
717 | ||
718 | /* | |
719 | * Return value: | |
720 | * 0: success | |
721 | * <0: error | |
722 | */ | |
723 | static | |
724 | int validate_instruction_all_contexts(struct bytecode_runtime *bytecode, | |
725 | struct mp_table *mp_table, | |
726 | struct vstack *stack, | |
727 | void *start_pc, | |
728 | void *pc) | |
729 | { | |
730 | int ret, found = 0; | |
731 | unsigned long target_pc = pc - start_pc; | |
732 | unsigned long hash; | |
733 | struct hlist_head *head; | |
734 | struct mp_node *mp_node; | |
735 | ||
736 | /* Validate the context resulting from the previous instruction */ | |
737 | ret = validate_instruction_context(bytecode, stack, start_pc, pc); | |
738 | if (ret) | |
739 | return ret; | |
740 | ||
741 | /* Validate merge points */ | |
742 | hash = jhash_1word(target_pc, 0); | |
743 | head = &mp_table->mp_head[hash & (MERGE_POINT_TABLE_SIZE - 1)]; | |
d216ecae | 744 | lttng_hlist_for_each_entry(mp_node, head, node) { |
07dfc1d0 MD |
745 | if (lttng_hash_match(mp_node, target_pc)) { |
746 | found = 1; | |
747 | break; | |
748 | } | |
749 | } | |
750 | if (found) { | |
751 | dbg_printk("Filter: validate merge point at offset %lu\n", | |
752 | target_pc); | |
753 | if (merge_points_compare(stack, &mp_node->stack)) { | |
754 | printk(KERN_WARNING "Merge points differ for offset %lu\n", | |
755 | target_pc); | |
756 | return -EINVAL; | |
757 | } | |
758 | /* Once validated, we can remove the merge point */ | |
759 | dbg_printk("Filter: remove merge point at offset %lu\n", | |
760 | target_pc); | |
761 | hlist_del(&mp_node->node); | |
762 | } | |
763 | return 0; | |
764 | } | |
765 | ||
766 | /* | |
767 | * Return value: | |
768 | * >0: going to next insn. | |
769 | * 0: success, stop iteration. | |
770 | * <0: error | |
771 | */ | |
772 | static | |
773 | int exec_insn(struct bytecode_runtime *bytecode, | |
774 | struct mp_table *mp_table, | |
775 | struct vstack *stack, | |
776 | void **_next_pc, | |
777 | void *pc) | |
778 | { | |
779 | int ret = 1; | |
780 | void *next_pc = *_next_pc; | |
781 | ||
782 | switch (*(filter_opcode_t *) pc) { | |
783 | case FILTER_OP_UNKNOWN: | |
784 | default: | |
785 | { | |
786 | printk(KERN_WARNING "unknown bytecode op %u\n", | |
787 | (unsigned int) *(filter_opcode_t *) pc); | |
788 | ret = -EINVAL; | |
789 | goto end; | |
790 | } | |
791 | ||
792 | case FILTER_OP_RETURN: | |
793 | { | |
794 | if (!vstack_ax(stack)) { | |
795 | printk(KERN_WARNING "Empty stack\n"); | |
796 | ret = -EINVAL; | |
797 | goto end; | |
798 | } | |
799 | ret = 0; | |
800 | goto end; | |
801 | } | |
802 | ||
803 | /* binary */ | |
804 | case FILTER_OP_MUL: | |
805 | case FILTER_OP_DIV: | |
806 | case FILTER_OP_MOD: | |
807 | case FILTER_OP_PLUS: | |
808 | case FILTER_OP_MINUS: | |
809 | case FILTER_OP_RSHIFT: | |
810 | case FILTER_OP_LSHIFT: | |
811 | case FILTER_OP_BIN_AND: | |
812 | case FILTER_OP_BIN_OR: | |
813 | case FILTER_OP_BIN_XOR: | |
814 | /* Floating point */ | |
815 | case FILTER_OP_EQ_DOUBLE: | |
816 | case FILTER_OP_NE_DOUBLE: | |
817 | case FILTER_OP_GT_DOUBLE: | |
818 | case FILTER_OP_LT_DOUBLE: | |
819 | case FILTER_OP_GE_DOUBLE: | |
820 | case FILTER_OP_LE_DOUBLE: | |
821 | case FILTER_OP_EQ_DOUBLE_S64: | |
822 | case FILTER_OP_NE_DOUBLE_S64: | |
823 | case FILTER_OP_GT_DOUBLE_S64: | |
824 | case FILTER_OP_LT_DOUBLE_S64: | |
825 | case FILTER_OP_GE_DOUBLE_S64: | |
826 | case FILTER_OP_LE_DOUBLE_S64: | |
827 | case FILTER_OP_EQ_S64_DOUBLE: | |
828 | case FILTER_OP_NE_S64_DOUBLE: | |
829 | case FILTER_OP_GT_S64_DOUBLE: | |
830 | case FILTER_OP_LT_S64_DOUBLE: | |
831 | case FILTER_OP_GE_S64_DOUBLE: | |
832 | case FILTER_OP_LE_S64_DOUBLE: | |
833 | case FILTER_OP_UNARY_PLUS_DOUBLE: | |
834 | case FILTER_OP_UNARY_MINUS_DOUBLE: | |
835 | case FILTER_OP_UNARY_NOT_DOUBLE: | |
836 | case FILTER_OP_LOAD_FIELD_REF_DOUBLE: | |
837 | case FILTER_OP_GET_CONTEXT_REF_DOUBLE: | |
838 | case FILTER_OP_LOAD_DOUBLE: | |
839 | case FILTER_OP_CAST_DOUBLE_TO_S64: | |
840 | { | |
841 | printk(KERN_WARNING "unsupported bytecode op %u\n", | |
842 | (unsigned int) *(filter_opcode_t *) pc); | |
843 | ret = -EINVAL; | |
844 | goto end; | |
845 | } | |
846 | ||
847 | case FILTER_OP_EQ: | |
848 | case FILTER_OP_NE: | |
849 | case FILTER_OP_GT: | |
850 | case FILTER_OP_LT: | |
851 | case FILTER_OP_GE: | |
852 | case FILTER_OP_LE: | |
853 | case FILTER_OP_EQ_STRING: | |
854 | case FILTER_OP_NE_STRING: | |
855 | case FILTER_OP_GT_STRING: | |
856 | case FILTER_OP_LT_STRING: | |
857 | case FILTER_OP_GE_STRING: | |
858 | case FILTER_OP_LE_STRING: | |
859 | case FILTER_OP_EQ_S64: | |
860 | case FILTER_OP_NE_S64: | |
861 | case FILTER_OP_GT_S64: | |
862 | case FILTER_OP_LT_S64: | |
863 | case FILTER_OP_GE_S64: | |
864 | case FILTER_OP_LE_S64: | |
865 | { | |
866 | /* Pop 2, push 1 */ | |
867 | if (vstack_pop(stack)) { | |
868 | ret = -EINVAL; | |
869 | goto end; | |
870 | } | |
871 | if (!vstack_ax(stack)) { | |
872 | printk(KERN_WARNING "Empty stack\n"); | |
873 | ret = -EINVAL; | |
874 | goto end; | |
875 | } | |
876 | vstack_ax(stack)->type = REG_S64; | |
877 | next_pc += sizeof(struct binary_op); | |
878 | break; | |
879 | } | |
880 | ||
881 | /* unary */ | |
882 | case FILTER_OP_UNARY_PLUS: | |
883 | case FILTER_OP_UNARY_MINUS: | |
884 | case FILTER_OP_UNARY_NOT: | |
885 | case FILTER_OP_UNARY_PLUS_S64: | |
886 | case FILTER_OP_UNARY_MINUS_S64: | |
887 | case FILTER_OP_UNARY_NOT_S64: | |
888 | { | |
889 | /* Pop 1, push 1 */ | |
890 | if (!vstack_ax(stack)) { | |
891 | printk(KERN_WARNING "Empty stack\n"); | |
892 | ret = -EINVAL; | |
893 | goto end; | |
894 | } | |
895 | vstack_ax(stack)->type = REG_S64; | |
896 | next_pc += sizeof(struct unary_op); | |
897 | break; | |
898 | } | |
899 | ||
900 | /* logical */ | |
901 | case FILTER_OP_AND: | |
902 | case FILTER_OP_OR: | |
903 | { | |
904 | struct logical_op *insn = (struct logical_op *) pc; | |
905 | int merge_ret; | |
906 | ||
907 | /* Add merge point to table */ | |
908 | merge_ret = merge_point_add_check(mp_table, | |
909 | insn->skip_offset, stack); | |
910 | if (merge_ret) { | |
911 | ret = merge_ret; | |
912 | goto end; | |
913 | } | |
914 | /* Continue to next instruction */ | |
915 | /* Pop 1 when jump not taken */ | |
916 | if (vstack_pop(stack)) { | |
917 | ret = -EINVAL; | |
918 | goto end; | |
919 | } | |
920 | next_pc += sizeof(struct logical_op); | |
921 | break; | |
922 | } | |
923 | ||
924 | /* load field ref */ | |
925 | case FILTER_OP_LOAD_FIELD_REF: | |
926 | { | |
927 | printk(KERN_WARNING "Unknown field ref type\n"); | |
928 | ret = -EINVAL; | |
929 | goto end; | |
930 | } | |
931 | /* get context ref */ | |
932 | case FILTER_OP_GET_CONTEXT_REF: | |
933 | { | |
934 | printk(KERN_WARNING "Unknown get context ref type\n"); | |
935 | ret = -EINVAL; | |
936 | goto end; | |
937 | } | |
938 | case FILTER_OP_LOAD_FIELD_REF_STRING: | |
939 | case FILTER_OP_LOAD_FIELD_REF_SEQUENCE: | |
940 | case FILTER_OP_GET_CONTEXT_REF_STRING: | |
f127e61e MD |
941 | case FILTER_OP_LOAD_FIELD_REF_USER_STRING: |
942 | case FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE: | |
07dfc1d0 MD |
943 | { |
944 | if (vstack_push(stack)) { | |
945 | ret = -EINVAL; | |
946 | goto end; | |
947 | } | |
948 | vstack_ax(stack)->type = REG_STRING; | |
949 | next_pc += sizeof(struct load_op) + sizeof(struct field_ref); | |
950 | break; | |
951 | } | |
952 | case FILTER_OP_LOAD_FIELD_REF_S64: | |
953 | case FILTER_OP_GET_CONTEXT_REF_S64: | |
954 | { | |
955 | if (vstack_push(stack)) { | |
956 | ret = -EINVAL; | |
957 | goto end; | |
958 | } | |
959 | vstack_ax(stack)->type = REG_S64; | |
960 | next_pc += sizeof(struct load_op) + sizeof(struct field_ref); | |
961 | break; | |
962 | } | |
963 | ||
964 | /* load from immediate operand */ | |
965 | case FILTER_OP_LOAD_STRING: | |
966 | { | |
967 | struct load_op *insn = (struct load_op *) pc; | |
968 | ||
969 | if (vstack_push(stack)) { | |
970 | ret = -EINVAL; | |
971 | goto end; | |
972 | } | |
973 | vstack_ax(stack)->type = REG_STRING; | |
974 | next_pc += sizeof(struct load_op) + strlen(insn->data) + 1; | |
975 | break; | |
976 | } | |
977 | ||
978 | case FILTER_OP_LOAD_S64: | |
979 | { | |
980 | if (vstack_push(stack)) { | |
981 | ret = -EINVAL; | |
982 | goto end; | |
983 | } | |
984 | vstack_ax(stack)->type = REG_S64; | |
985 | next_pc += sizeof(struct load_op) | |
986 | + sizeof(struct literal_numeric); | |
987 | break; | |
988 | } | |
989 | ||
990 | case FILTER_OP_CAST_TO_S64: | |
991 | { | |
992 | /* Pop 1, push 1 */ | |
993 | if (!vstack_ax(stack)) { | |
994 | printk(KERN_WARNING "Empty stack\n"); | |
995 | ret = -EINVAL; | |
996 | goto end; | |
997 | } | |
998 | vstack_ax(stack)->type = REG_S64; | |
999 | next_pc += sizeof(struct cast_op); | |
1000 | break; | |
1001 | } | |
1002 | case FILTER_OP_CAST_NOP: | |
1003 | { | |
1004 | next_pc += sizeof(struct cast_op); | |
1005 | break; | |
1006 | } | |
1007 | ||
1008 | } | |
1009 | end: | |
1010 | *_next_pc = next_pc; | |
1011 | return ret; | |
1012 | } | |
1013 | ||
1014 | /* | |
1015 | * Never called concurrently (hash seed is shared). | |
1016 | */ | |
1017 | int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode) | |
1018 | { | |
1019 | struct mp_table *mp_table; | |
1020 | void *pc, *next_pc, *start_pc; | |
1021 | int ret = -EINVAL; | |
1022 | struct vstack stack; | |
1023 | ||
1024 | vstack_init(&stack); | |
1025 | ||
1026 | mp_table = kzalloc(sizeof(*mp_table), GFP_KERNEL); | |
1027 | if (!mp_table) { | |
1028 | printk(KERN_WARNING "Error allocating hash table for bytecode validation\n"); | |
1029 | return -ENOMEM; | |
1030 | } | |
1031 | start_pc = &bytecode->data[0]; | |
1032 | for (pc = next_pc = start_pc; pc - start_pc < bytecode->len; | |
1033 | pc = next_pc) { | |
1034 | ret = bytecode_validate_overflow(bytecode, start_pc, pc); | |
1035 | if (ret != 0) { | |
1036 | if (ret == -ERANGE) | |
1037 | printk(KERN_WARNING "filter bytecode overflow\n"); | |
1038 | goto end; | |
1039 | } | |
1040 | dbg_printk("Validating op %s (%u)\n", | |
1041 | lttng_filter_print_op((unsigned int) *(filter_opcode_t *) pc), | |
1042 | (unsigned int) *(filter_opcode_t *) pc); | |
1043 | ||
1044 | /* | |
1045 | * For each instruction, validate the current context | |
1046 | * (traversal of entire execution flow), and validate | |
1047 | * all merge points targeting this instruction. | |
1048 | */ | |
1049 | ret = validate_instruction_all_contexts(bytecode, mp_table, | |
1050 | &stack, start_pc, pc); | |
1051 | if (ret) | |
1052 | goto end; | |
1053 | ret = exec_insn(bytecode, mp_table, &stack, &next_pc, pc); | |
1054 | if (ret <= 0) | |
1055 | goto end; | |
1056 | } | |
1057 | end: | |
1058 | if (delete_all_nodes(mp_table)) { | |
1059 | if (!ret) { | |
1060 | printk(KERN_WARNING "Unexpected merge points\n"); | |
1061 | ret = -EINVAL; | |
1062 | } | |
1063 | } | |
1064 | kfree(mp_table); | |
1065 | return ret; | |
1066 | } |