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