1 /* SPDX-License-Identifier: MIT
3 * lttng-filter-validator.c
5 * LTTng modules filter bytecode validator.
7 * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
10 #include <linux/types.h>
11 #include <linux/jhash.h>
12 #include <linux/slab.h>
14 #include <wrapper/list.h>
15 #include <lttng-filter.h>
17 #define MERGE_POINT_TABLE_BITS 7
18 #define MERGE_POINT_TABLE_SIZE (1U << MERGE_POINT_TABLE_BITS)
20 /* merge point table node */
22 struct hlist_node node
;
24 /* Context at merge point */
26 unsigned long target_pc
;
30 struct hlist_head mp_head
[MERGE_POINT_TABLE_SIZE
];
34 int lttng_hash_match(struct mp_node
*mp_node
, unsigned long key_pc
)
36 if (mp_node
->target_pc
== key_pc
)
43 int merge_points_compare(const struct vstack
*stacka
,
44 const struct vstack
*stackb
)
48 if (stacka
->top
!= stackb
->top
)
50 len
= stacka
->top
+ 1;
51 WARN_ON_ONCE(len
< 0);
52 for (i
= 0; i
< len
; i
++) {
53 if (stacka
->e
[i
].type
!= stackb
->e
[i
].type
)
60 int merge_point_add_check(struct mp_table
*mp_table
, unsigned long target_pc
,
61 const struct vstack
*stack
)
63 struct mp_node
*mp_node
;
64 unsigned long hash
= jhash_1word(target_pc
, 0);
65 struct hlist_head
*head
;
66 struct mp_node
*lookup_node
;
69 dbg_printk("Filter: adding merge point at offset %lu, hash %lu\n",
71 mp_node
= kzalloc(sizeof(struct mp_node
), GFP_KERNEL
);
74 mp_node
->target_pc
= target_pc
;
75 memcpy(&mp_node
->stack
, stack
, sizeof(mp_node
->stack
));
77 head
= &mp_table
->mp_head
[hash
& (MERGE_POINT_TABLE_SIZE
- 1)];
78 lttng_hlist_for_each_entry(lookup_node
, head
, node
) {
79 if (lttng_hash_match(lookup_node
, target_pc
)) {
85 /* Key already present */
86 dbg_printk("Filter: compare merge points for offset %lu, hash %lu\n",
89 if (merge_points_compare(stack
, &lookup_node
->stack
)) {
90 printk(KERN_WARNING
"Merge points differ for offset %lu\n",
95 hlist_add_head(&mp_node
->node
, head
);
101 * Binary comparators use top of stack and top of stack -1.
104 int bin_op_compare_check(struct vstack
*stack
, const filter_opcode_t opcode
,
107 if (unlikely(!vstack_ax(stack
) || !vstack_bx(stack
)))
110 switch (vstack_ax(stack
)->type
) {
116 switch (vstack_bx(stack
)->type
) {
120 case REG_TYPE_UNKNOWN
:
124 case REG_STAR_GLOB_STRING
:
125 if (opcode
!= FILTER_OP_EQ
&& opcode
!= FILTER_OP_NE
) {
133 case REG_STAR_GLOB_STRING
:
134 switch (vstack_bx(stack
)->type
) {
138 case REG_TYPE_UNKNOWN
:
141 if (opcode
!= FILTER_OP_EQ
&& opcode
!= FILTER_OP_NE
) {
145 case REG_STAR_GLOB_STRING
:
151 switch (vstack_bx(stack
)->type
) {
155 case REG_TYPE_UNKNOWN
:
158 case REG_STAR_GLOB_STRING
:
164 case REG_TYPE_UNKNOWN
:
165 switch (vstack_bx(stack
)->type
) {
169 case REG_TYPE_UNKNOWN
:
171 case REG_STAR_GLOB_STRING
:
183 printk(KERN_WARNING
"empty stack for '%s' binary operator\n", str
);
187 printk(KERN_WARNING
"type mismatch for '%s' binary operator\n", str
);
191 printk(KERN_WARNING
"unknown type for '%s' binary operator\n", str
);
196 * Binary bitwise operators use top of stack and top of stack -1.
197 * Return 0 if typing is known to match, 1 if typing is dynamic
198 * (unknown), negative error value on error.
201 int bin_op_bitwise_check(struct vstack
*stack
, filter_opcode_t opcode
,
204 if (unlikely(!vstack_ax(stack
) || !vstack_bx(stack
)))
207 switch (vstack_ax(stack
)->type
) {
212 case REG_TYPE_UNKNOWN
:
213 switch (vstack_bx(stack
)->type
) {
217 case REG_TYPE_UNKNOWN
:
219 case REG_STAR_GLOB_STRING
:
225 switch (vstack_bx(stack
)->type
) {
229 case REG_TYPE_UNKNOWN
:
242 printk(KERN_WARNING
"empty stack for '%s' binary operator\n", str
);
246 printk(KERN_WARNING
"unknown type for '%s' binary operator\n", str
);
251 int validate_get_symbol(struct bytecode_runtime
*bytecode
,
252 const struct get_symbol
*sym
)
254 const char *str
, *str_limit
;
257 if (sym
->offset
>= bytecode
->p
.bc
->bc
.len
- bytecode
->p
.bc
->bc
.reloc_offset
)
260 str
= bytecode
->p
.bc
->bc
.data
+ bytecode
->p
.bc
->bc
.reloc_offset
+ sym
->offset
;
261 str_limit
= bytecode
->p
.bc
->bc
.data
+ bytecode
->p
.bc
->bc
.len
;
262 len_limit
= str_limit
- str
;
263 if (strnlen(str
, len_limit
) == len_limit
)
269 * Validate bytecode range overflow within the validation pass.
270 * Called for each instruction encountered.
273 int bytecode_validate_overflow(struct bytecode_runtime
*bytecode
,
274 char *start_pc
, char *pc
)
278 switch (*(filter_opcode_t
*) pc
) {
279 case FILTER_OP_UNKNOWN
:
282 printk(KERN_WARNING
"unknown bytecode op %u\n",
283 (unsigned int) *(filter_opcode_t
*) pc
);
288 case FILTER_OP_RETURN
:
289 case FILTER_OP_RETURN_S64
:
291 if (unlikely(pc
+ sizeof(struct return_op
)
292 > start_pc
+ bytecode
->len
)) {
303 case FILTER_OP_MINUS
:
304 case FILTER_OP_EQ_DOUBLE
:
305 case FILTER_OP_NE_DOUBLE
:
306 case FILTER_OP_GT_DOUBLE
:
307 case FILTER_OP_LT_DOUBLE
:
308 case FILTER_OP_GE_DOUBLE
:
309 case FILTER_OP_LE_DOUBLE
:
311 case FILTER_OP_EQ_DOUBLE_S64
:
312 case FILTER_OP_NE_DOUBLE_S64
:
313 case FILTER_OP_GT_DOUBLE_S64
:
314 case FILTER_OP_LT_DOUBLE_S64
:
315 case FILTER_OP_GE_DOUBLE_S64
:
316 case FILTER_OP_LE_DOUBLE_S64
:
317 case FILTER_OP_EQ_S64_DOUBLE
:
318 case FILTER_OP_NE_S64_DOUBLE
:
319 case FILTER_OP_GT_S64_DOUBLE
:
320 case FILTER_OP_LT_S64_DOUBLE
:
321 case FILTER_OP_GE_S64_DOUBLE
:
322 case FILTER_OP_LE_S64_DOUBLE
:
323 case FILTER_OP_LOAD_FIELD_REF_DOUBLE
:
324 case FILTER_OP_GET_CONTEXT_REF_DOUBLE
:
325 case FILTER_OP_LOAD_DOUBLE
:
326 case FILTER_OP_CAST_DOUBLE_TO_S64
:
327 case FILTER_OP_UNARY_PLUS_DOUBLE
:
328 case FILTER_OP_UNARY_MINUS_DOUBLE
:
329 case FILTER_OP_UNARY_NOT_DOUBLE
:
331 printk(KERN_WARNING
"unsupported bytecode op %u\n",
332 (unsigned int) *(filter_opcode_t
*) pc
);
343 case FILTER_OP_EQ_STRING
:
344 case FILTER_OP_NE_STRING
:
345 case FILTER_OP_GT_STRING
:
346 case FILTER_OP_LT_STRING
:
347 case FILTER_OP_GE_STRING
:
348 case FILTER_OP_LE_STRING
:
349 case FILTER_OP_EQ_STAR_GLOB_STRING
:
350 case FILTER_OP_NE_STAR_GLOB_STRING
:
351 case FILTER_OP_EQ_S64
:
352 case FILTER_OP_NE_S64
:
353 case FILTER_OP_GT_S64
:
354 case FILTER_OP_LT_S64
:
355 case FILTER_OP_GE_S64
:
356 case FILTER_OP_LE_S64
:
357 case FILTER_OP_BIT_RSHIFT
:
358 case FILTER_OP_BIT_LSHIFT
:
359 case FILTER_OP_BIT_AND
:
360 case FILTER_OP_BIT_OR
:
361 case FILTER_OP_BIT_XOR
:
363 if (unlikely(pc
+ sizeof(struct binary_op
)
364 > start_pc
+ bytecode
->len
)) {
371 case FILTER_OP_UNARY_PLUS
:
372 case FILTER_OP_UNARY_MINUS
:
373 case FILTER_OP_UNARY_NOT
:
374 case FILTER_OP_UNARY_PLUS_S64
:
375 case FILTER_OP_UNARY_MINUS_S64
:
376 case FILTER_OP_UNARY_NOT_S64
:
377 case FILTER_OP_UNARY_BIT_NOT
:
379 if (unlikely(pc
+ sizeof(struct unary_op
)
380 > start_pc
+ bytecode
->len
)) {
390 if (unlikely(pc
+ sizeof(struct logical_op
)
391 > start_pc
+ bytecode
->len
)) {
398 case FILTER_OP_LOAD_FIELD_REF
:
400 printk(KERN_WARNING
"Unknown field ref type\n");
405 /* get context ref */
406 case FILTER_OP_GET_CONTEXT_REF
:
408 printk(KERN_WARNING
"Unknown field ref type\n");
412 case FILTER_OP_LOAD_FIELD_REF_STRING
:
413 case FILTER_OP_LOAD_FIELD_REF_SEQUENCE
:
414 case FILTER_OP_LOAD_FIELD_REF_USER_STRING
:
415 case FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE
:
416 case FILTER_OP_LOAD_FIELD_REF_S64
:
417 case FILTER_OP_GET_CONTEXT_REF_STRING
:
418 case FILTER_OP_GET_CONTEXT_REF_S64
:
420 if (unlikely(pc
+ sizeof(struct load_op
) + sizeof(struct field_ref
)
421 > start_pc
+ bytecode
->len
)) {
427 /* load from immediate operand */
428 case FILTER_OP_LOAD_STRING
:
429 case FILTER_OP_LOAD_STAR_GLOB_STRING
:
431 struct load_op
*insn
= (struct load_op
*) pc
;
432 uint32_t str_len
, maxlen
;
434 if (unlikely(pc
+ sizeof(struct load_op
)
435 > start_pc
+ bytecode
->len
)) {
440 maxlen
= start_pc
+ bytecode
->len
- pc
- sizeof(struct load_op
);
441 str_len
= strnlen(insn
->data
, maxlen
);
442 if (unlikely(str_len
>= maxlen
)) {
443 /* Final '\0' not found within range */
449 case FILTER_OP_LOAD_S64
:
451 if (unlikely(pc
+ sizeof(struct load_op
) + sizeof(struct literal_numeric
)
452 > start_pc
+ bytecode
->len
)) {
458 case FILTER_OP_CAST_TO_S64
:
459 case FILTER_OP_CAST_NOP
:
461 if (unlikely(pc
+ sizeof(struct cast_op
)
462 > start_pc
+ bytecode
->len
)) {
469 * Instructions for recursive traversal through composed types.
471 case FILTER_OP_GET_CONTEXT_ROOT
:
472 case FILTER_OP_GET_APP_CONTEXT_ROOT
:
473 case FILTER_OP_GET_PAYLOAD_ROOT
:
474 case FILTER_OP_LOAD_FIELD
:
475 case FILTER_OP_LOAD_FIELD_S8
:
476 case FILTER_OP_LOAD_FIELD_S16
:
477 case FILTER_OP_LOAD_FIELD_S32
:
478 case FILTER_OP_LOAD_FIELD_S64
:
479 case FILTER_OP_LOAD_FIELD_U8
:
480 case FILTER_OP_LOAD_FIELD_U16
:
481 case FILTER_OP_LOAD_FIELD_U32
:
482 case FILTER_OP_LOAD_FIELD_U64
:
483 case FILTER_OP_LOAD_FIELD_STRING
:
484 case FILTER_OP_LOAD_FIELD_SEQUENCE
:
485 case FILTER_OP_LOAD_FIELD_DOUBLE
:
486 if (unlikely(pc
+ sizeof(struct load_op
)
487 > start_pc
+ bytecode
->len
)) {
492 case FILTER_OP_GET_SYMBOL
:
494 struct load_op
*insn
= (struct load_op
*) pc
;
495 struct get_symbol
*sym
= (struct get_symbol
*) insn
->data
;
497 if (unlikely(pc
+ sizeof(struct load_op
) + sizeof(struct get_symbol
)
498 > start_pc
+ bytecode
->len
)) {
502 ret
= validate_get_symbol(bytecode
, sym
);
506 case FILTER_OP_GET_SYMBOL_FIELD
:
507 printk(KERN_WARNING
"Unexpected get symbol field\n");
511 case FILTER_OP_GET_INDEX_U16
:
512 if (unlikely(pc
+ sizeof(struct load_op
) + sizeof(struct get_index_u16
)
513 > start_pc
+ bytecode
->len
)) {
518 case FILTER_OP_GET_INDEX_U64
:
519 if (unlikely(pc
+ sizeof(struct load_op
) + sizeof(struct get_index_u64
)
520 > start_pc
+ bytecode
->len
)) {
530 unsigned long delete_all_nodes(struct mp_table
*mp_table
)
532 struct mp_node
*mp_node
;
533 struct hlist_node
*tmp
;
534 unsigned long nr_nodes
= 0;
537 for (i
= 0; i
< MERGE_POINT_TABLE_SIZE
; i
++) {
538 struct hlist_head
*head
;
540 head
= &mp_table
->mp_head
[i
];
541 lttng_hlist_for_each_entry_safe(mp_node
, tmp
, head
, node
) {
555 int validate_instruction_context(struct bytecode_runtime
*bytecode
,
556 struct vstack
*stack
,
561 const filter_opcode_t opcode
= *(filter_opcode_t
*) pc
;
564 case FILTER_OP_UNKNOWN
:
567 printk(KERN_WARNING
"unknown bytecode op %u\n",
568 (unsigned int) *(filter_opcode_t
*) pc
);
573 case FILTER_OP_RETURN
:
574 case FILTER_OP_RETURN_S64
:
584 case FILTER_OP_MINUS
:
586 case FILTER_OP_EQ_DOUBLE
:
587 case FILTER_OP_NE_DOUBLE
:
588 case FILTER_OP_GT_DOUBLE
:
589 case FILTER_OP_LT_DOUBLE
:
590 case FILTER_OP_GE_DOUBLE
:
591 case FILTER_OP_LE_DOUBLE
:
592 case FILTER_OP_EQ_DOUBLE_S64
:
593 case FILTER_OP_NE_DOUBLE_S64
:
594 case FILTER_OP_GT_DOUBLE_S64
:
595 case FILTER_OP_LT_DOUBLE_S64
:
596 case FILTER_OP_GE_DOUBLE_S64
:
597 case FILTER_OP_LE_DOUBLE_S64
:
598 case FILTER_OP_EQ_S64_DOUBLE
:
599 case FILTER_OP_NE_S64_DOUBLE
:
600 case FILTER_OP_GT_S64_DOUBLE
:
601 case FILTER_OP_LT_S64_DOUBLE
:
602 case FILTER_OP_GE_S64_DOUBLE
:
603 case FILTER_OP_LE_S64_DOUBLE
:
604 case FILTER_OP_UNARY_PLUS_DOUBLE
:
605 case FILTER_OP_UNARY_MINUS_DOUBLE
:
606 case FILTER_OP_UNARY_NOT_DOUBLE
:
607 case FILTER_OP_LOAD_FIELD_REF_DOUBLE
:
608 case FILTER_OP_LOAD_DOUBLE
:
609 case FILTER_OP_CAST_DOUBLE_TO_S64
:
610 case FILTER_OP_GET_CONTEXT_REF_DOUBLE
:
612 printk(KERN_WARNING
"unsupported bytecode op %u\n",
613 (unsigned int) *(filter_opcode_t
*) pc
);
620 ret
= bin_op_compare_check(stack
, opcode
, "==");
627 ret
= bin_op_compare_check(stack
, opcode
, "!=");
634 ret
= bin_op_compare_check(stack
, opcode
, ">");
641 ret
= bin_op_compare_check(stack
, opcode
, "<");
648 ret
= bin_op_compare_check(stack
, opcode
, ">=");
655 ret
= bin_op_compare_check(stack
, opcode
, "<=");
661 case FILTER_OP_EQ_STRING
:
662 case FILTER_OP_NE_STRING
:
663 case FILTER_OP_GT_STRING
:
664 case FILTER_OP_LT_STRING
:
665 case FILTER_OP_GE_STRING
:
666 case FILTER_OP_LE_STRING
:
668 if (!vstack_ax(stack
) || !vstack_bx(stack
)) {
669 printk(KERN_WARNING
"Empty stack\n");
673 if (vstack_ax(stack
)->type
!= REG_STRING
674 || vstack_bx(stack
)->type
!= REG_STRING
) {
675 printk(KERN_WARNING
"Unexpected register type for string comparator\n");
683 case FILTER_OP_EQ_STAR_GLOB_STRING
:
684 case FILTER_OP_NE_STAR_GLOB_STRING
:
686 if (!vstack_ax(stack
) || !vstack_bx(stack
)) {
687 printk(KERN_WARNING
"Empty stack\n");
691 if (vstack_ax(stack
)->type
!= REG_STAR_GLOB_STRING
692 && vstack_bx(stack
)->type
!= REG_STAR_GLOB_STRING
) {
693 printk(KERN_WARNING
"Unexpected register type for globbing pattern comparator\n");
700 case FILTER_OP_EQ_S64
:
701 case FILTER_OP_NE_S64
:
702 case FILTER_OP_GT_S64
:
703 case FILTER_OP_LT_S64
:
704 case FILTER_OP_GE_S64
:
705 case FILTER_OP_LE_S64
:
707 if (!vstack_ax(stack
) || !vstack_bx(stack
)) {
708 printk(KERN_WARNING
"Empty stack\n");
712 if (vstack_ax(stack
)->type
!= REG_S64
713 || vstack_bx(stack
)->type
!= REG_S64
) {
714 printk(KERN_WARNING
"Unexpected register type for s64 comparator\n");
721 case FILTER_OP_BIT_RSHIFT
:
722 ret
= bin_op_bitwise_check(stack
, opcode
, ">>");
726 case FILTER_OP_BIT_LSHIFT
:
727 ret
= bin_op_bitwise_check(stack
, opcode
, "<<");
731 case FILTER_OP_BIT_AND
:
732 ret
= bin_op_bitwise_check(stack
, opcode
, "&");
736 case FILTER_OP_BIT_OR
:
737 ret
= bin_op_bitwise_check(stack
, opcode
, "|");
741 case FILTER_OP_BIT_XOR
:
742 ret
= bin_op_bitwise_check(stack
, opcode
, "^");
748 case FILTER_OP_UNARY_PLUS
:
749 case FILTER_OP_UNARY_MINUS
:
750 case FILTER_OP_UNARY_NOT
:
752 if (!vstack_ax(stack
)) {
753 printk(KERN_WARNING
"Empty stack\n");
757 switch (vstack_ax(stack
)->type
) {
760 printk(KERN_WARNING
"unknown register type\n");
765 case REG_STAR_GLOB_STRING
:
766 printk(KERN_WARNING
"Unary op can only be applied to numeric or floating point registers\n");
770 case REG_TYPE_UNKNOWN
:
775 case FILTER_OP_UNARY_BIT_NOT
:
777 if (!vstack_ax(stack
)) {
778 printk(KERN_WARNING
"Empty stack\n");
782 switch (vstack_ax(stack
)->type
) {
784 printk(KERN_WARNING
"unknown register type\n");
789 case REG_STAR_GLOB_STRING
:
791 printk(KERN_WARNING
"Unary bitwise op can only be applied to numeric registers\n");
796 case REG_TYPE_UNKNOWN
:
802 case FILTER_OP_UNARY_PLUS_S64
:
803 case FILTER_OP_UNARY_MINUS_S64
:
804 case FILTER_OP_UNARY_NOT_S64
:
806 if (!vstack_ax(stack
)) {
807 printk(KERN_WARNING
"Empty stack\n");
811 if (vstack_ax(stack
)->type
!= REG_S64
) {
812 printk(KERN_WARNING
"Invalid register type\n");
823 struct logical_op
*insn
= (struct logical_op
*) pc
;
825 if (!vstack_ax(stack
)) {
826 printk(KERN_WARNING
"Empty stack\n");
830 if (vstack_ax(stack
)->type
!= REG_S64
) {
831 printk(KERN_WARNING
"Logical comparator expects S64 register\n");
836 dbg_printk("Validate jumping to bytecode offset %u\n",
837 (unsigned int) insn
->skip_offset
);
838 if (unlikely(start_pc
+ insn
->skip_offset
<= pc
)) {
839 printk(KERN_WARNING
"Loops are not allowed in bytecode\n");
847 case FILTER_OP_LOAD_FIELD_REF
:
849 printk(KERN_WARNING
"Unknown field ref type\n");
853 case FILTER_OP_LOAD_FIELD_REF_STRING
:
854 case FILTER_OP_LOAD_FIELD_REF_SEQUENCE
:
855 case FILTER_OP_LOAD_FIELD_REF_USER_STRING
:
856 case FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE
:
858 struct load_op
*insn
= (struct load_op
*) pc
;
859 struct field_ref
*ref
= (struct field_ref
*) insn
->data
;
861 dbg_printk("Validate load field ref offset %u type string\n",
865 case FILTER_OP_LOAD_FIELD_REF_S64
:
867 struct load_op
*insn
= (struct load_op
*) pc
;
868 struct field_ref
*ref
= (struct field_ref
*) insn
->data
;
870 dbg_printk("Validate load field ref offset %u type s64\n",
875 /* load from immediate operand */
876 case FILTER_OP_LOAD_STRING
:
877 case FILTER_OP_LOAD_STAR_GLOB_STRING
:
882 case FILTER_OP_LOAD_S64
:
887 case FILTER_OP_CAST_TO_S64
:
889 struct cast_op
*insn
= (struct cast_op
*) pc
;
891 if (!vstack_ax(stack
)) {
892 printk(KERN_WARNING
"Empty stack\n");
896 switch (vstack_ax(stack
)->type
) {
899 printk(KERN_WARNING
"unknown register type\n");
904 case REG_STAR_GLOB_STRING
:
905 printk(KERN_WARNING
"Cast op can only be applied to numeric or floating point registers\n");
911 if (insn
->op
== FILTER_OP_CAST_DOUBLE_TO_S64
) {
912 if (vstack_ax(stack
)->type
!= REG_DOUBLE
) {
913 printk(KERN_WARNING
"Cast expects double\n");
920 case FILTER_OP_CAST_NOP
:
925 /* get context ref */
926 case FILTER_OP_GET_CONTEXT_REF
:
928 printk(KERN_WARNING
"Unknown get context ref type\n");
932 case FILTER_OP_GET_CONTEXT_REF_STRING
:
934 struct load_op
*insn
= (struct load_op
*) pc
;
935 struct field_ref
*ref
= (struct field_ref
*) insn
->data
;
937 dbg_printk("Validate get context ref offset %u type string\n",
941 case FILTER_OP_GET_CONTEXT_REF_S64
:
943 struct load_op
*insn
= (struct load_op
*) pc
;
944 struct field_ref
*ref
= (struct field_ref
*) insn
->data
;
946 dbg_printk("Validate get context ref offset %u type s64\n",
952 * Instructions for recursive traversal through composed types.
954 case FILTER_OP_GET_CONTEXT_ROOT
:
956 dbg_printk("Validate get context root\n");
959 case FILTER_OP_GET_APP_CONTEXT_ROOT
:
961 dbg_printk("Validate get app context root\n");
964 case FILTER_OP_GET_PAYLOAD_ROOT
:
966 dbg_printk("Validate get payload root\n");
969 case FILTER_OP_LOAD_FIELD
:
972 * We tolerate that field type is unknown at validation,
973 * because we are performing the load specialization in
974 * a phase after validation.
976 dbg_printk("Validate load field\n");
981 * Disallow already specialized bytecode op load field instructions to
982 * ensure that the received bytecode does not:
984 * - Read user-space memory without proper get_user accessors,
985 * - Read a memory area larger than the memory targeted by the instrumentation.
987 case FILTER_OP_LOAD_FIELD_S8
:
988 case FILTER_OP_LOAD_FIELD_S16
:
989 case FILTER_OP_LOAD_FIELD_S32
:
990 case FILTER_OP_LOAD_FIELD_S64
:
991 case FILTER_OP_LOAD_FIELD_U8
:
992 case FILTER_OP_LOAD_FIELD_U16
:
993 case FILTER_OP_LOAD_FIELD_U32
:
994 case FILTER_OP_LOAD_FIELD_U64
:
995 case FILTER_OP_LOAD_FIELD_STRING
:
996 case FILTER_OP_LOAD_FIELD_SEQUENCE
:
997 case FILTER_OP_LOAD_FIELD_DOUBLE
:
999 dbg_printk("Validate load field, reject specialized load instruction (%d)\n",
1005 case FILTER_OP_GET_SYMBOL
:
1007 struct load_op
*insn
= (struct load_op
*) pc
;
1008 struct get_symbol
*sym
= (struct get_symbol
*) insn
->data
;
1010 dbg_printk("Validate get symbol offset %u\n", sym
->offset
);
1014 case FILTER_OP_GET_SYMBOL_FIELD
:
1016 struct load_op
*insn
= (struct load_op
*) pc
;
1017 struct get_symbol
*sym
= (struct get_symbol
*) insn
->data
;
1019 dbg_printk("Validate get symbol field offset %u\n", sym
->offset
);
1023 case FILTER_OP_GET_INDEX_U16
:
1025 struct load_op
*insn
= (struct load_op
*) pc
;
1026 struct get_index_u16
*get_index
= (struct get_index_u16
*) insn
->data
;
1028 dbg_printk("Validate get index u16 index %u\n", get_index
->index
);
1032 case FILTER_OP_GET_INDEX_U64
:
1034 struct load_op
*insn
= (struct load_op
*) pc
;
1035 struct get_index_u64
*get_index
= (struct get_index_u64
*) insn
->data
;
1037 dbg_printk("Validate get index u64 index %llu\n",
1038 (unsigned long long) get_index
->index
);
1052 int validate_instruction_all_contexts(struct bytecode_runtime
*bytecode
,
1053 struct mp_table
*mp_table
,
1054 struct vstack
*stack
,
1059 unsigned long target_pc
= pc
- start_pc
;
1061 struct hlist_head
*head
;
1062 struct mp_node
*mp_node
;
1064 /* Validate the context resulting from the previous instruction */
1065 ret
= validate_instruction_context(bytecode
, stack
, start_pc
, pc
);
1069 /* Validate merge points */
1070 hash
= jhash_1word(target_pc
, 0);
1071 head
= &mp_table
->mp_head
[hash
& (MERGE_POINT_TABLE_SIZE
- 1)];
1072 lttng_hlist_for_each_entry(mp_node
, head
, node
) {
1073 if (lttng_hash_match(mp_node
, target_pc
)) {
1079 dbg_printk("Filter: validate merge point at offset %lu\n",
1081 if (merge_points_compare(stack
, &mp_node
->stack
)) {
1082 printk(KERN_WARNING
"Merge points differ for offset %lu\n",
1086 /* Once validated, we can remove the merge point */
1087 dbg_printk("Filter: remove merge point at offset %lu\n",
1089 hlist_del(&mp_node
->node
);
1096 * >0: going to next insn.
1097 * 0: success, stop iteration.
1101 int exec_insn(struct bytecode_runtime
*bytecode
,
1102 struct mp_table
*mp_table
,
1103 struct vstack
*stack
,
1108 char *next_pc
= *_next_pc
;
1110 switch (*(filter_opcode_t
*) pc
) {
1111 case FILTER_OP_UNKNOWN
:
1114 printk(KERN_WARNING
"unknown bytecode op %u\n",
1115 (unsigned int) *(filter_opcode_t
*) pc
);
1120 case FILTER_OP_RETURN
:
1122 if (!vstack_ax(stack
)) {
1123 printk(KERN_WARNING
"Empty stack\n");
1127 switch (vstack_ax(stack
)->type
) {
1129 case REG_TYPE_UNKNOWN
:
1132 printk(KERN_WARNING
"Unexpected register type %d at end of bytecode\n",
1133 (int) vstack_ax(stack
)->type
);
1142 case FILTER_OP_RETURN_S64
:
1144 if (!vstack_ax(stack
)) {
1145 printk(KERN_WARNING
"Empty stack\n");
1149 switch (vstack_ax(stack
)->type
) {
1153 case REG_TYPE_UNKNOWN
:
1154 printk(KERN_WARNING
"Unexpected register type %d at end of bytecode\n",
1155 (int) vstack_ax(stack
)->type
);
1168 case FILTER_OP_PLUS
:
1169 case FILTER_OP_MINUS
:
1170 /* Floating point */
1171 case FILTER_OP_EQ_DOUBLE
:
1172 case FILTER_OP_NE_DOUBLE
:
1173 case FILTER_OP_GT_DOUBLE
:
1174 case FILTER_OP_LT_DOUBLE
:
1175 case FILTER_OP_GE_DOUBLE
:
1176 case FILTER_OP_LE_DOUBLE
:
1177 case FILTER_OP_EQ_DOUBLE_S64
:
1178 case FILTER_OP_NE_DOUBLE_S64
:
1179 case FILTER_OP_GT_DOUBLE_S64
:
1180 case FILTER_OP_LT_DOUBLE_S64
:
1181 case FILTER_OP_GE_DOUBLE_S64
:
1182 case FILTER_OP_LE_DOUBLE_S64
:
1183 case FILTER_OP_EQ_S64_DOUBLE
:
1184 case FILTER_OP_NE_S64_DOUBLE
:
1185 case FILTER_OP_GT_S64_DOUBLE
:
1186 case FILTER_OP_LT_S64_DOUBLE
:
1187 case FILTER_OP_GE_S64_DOUBLE
:
1188 case FILTER_OP_LE_S64_DOUBLE
:
1189 case FILTER_OP_UNARY_PLUS_DOUBLE
:
1190 case FILTER_OP_UNARY_MINUS_DOUBLE
:
1191 case FILTER_OP_UNARY_NOT_DOUBLE
:
1192 case FILTER_OP_LOAD_FIELD_REF_DOUBLE
:
1193 case FILTER_OP_GET_CONTEXT_REF_DOUBLE
:
1194 case FILTER_OP_LOAD_DOUBLE
:
1195 case FILTER_OP_CAST_DOUBLE_TO_S64
:
1197 printk(KERN_WARNING
"unsupported bytecode op %u\n",
1198 (unsigned int) *(filter_opcode_t
*) pc
);
1209 case FILTER_OP_EQ_STRING
:
1210 case FILTER_OP_NE_STRING
:
1211 case FILTER_OP_GT_STRING
:
1212 case FILTER_OP_LT_STRING
:
1213 case FILTER_OP_GE_STRING
:
1214 case FILTER_OP_LE_STRING
:
1215 case FILTER_OP_EQ_STAR_GLOB_STRING
:
1216 case FILTER_OP_NE_STAR_GLOB_STRING
:
1217 case FILTER_OP_EQ_S64
:
1218 case FILTER_OP_NE_S64
:
1219 case FILTER_OP_GT_S64
:
1220 case FILTER_OP_LT_S64
:
1221 case FILTER_OP_GE_S64
:
1222 case FILTER_OP_LE_S64
:
1223 case FILTER_OP_BIT_RSHIFT
:
1224 case FILTER_OP_BIT_LSHIFT
:
1225 case FILTER_OP_BIT_AND
:
1226 case FILTER_OP_BIT_OR
:
1227 case FILTER_OP_BIT_XOR
:
1230 if (vstack_pop(stack
)) {
1234 if (!vstack_ax(stack
)) {
1235 printk(KERN_WARNING
"Empty stack\n");
1239 switch (vstack_ax(stack
)->type
) {
1243 case REG_STAR_GLOB_STRING
:
1244 case REG_TYPE_UNKNOWN
:
1247 printk(KERN_WARNING
"Unexpected register type %d for operation\n",
1248 (int) vstack_ax(stack
)->type
);
1253 vstack_ax(stack
)->type
= REG_S64
;
1254 next_pc
+= sizeof(struct binary_op
);
1259 case FILTER_OP_UNARY_PLUS
:
1260 case FILTER_OP_UNARY_MINUS
:
1263 if (!vstack_ax(stack
)) {
1264 printk(KERN_WARNING
"Empty stack\n\n");
1268 switch (vstack_ax(stack
)->type
) {
1270 case REG_TYPE_UNKNOWN
:
1273 printk(KERN_WARNING
"Unexpected register type %d for operation\n",
1274 (int) vstack_ax(stack
)->type
);
1279 vstack_ax(stack
)->type
= REG_TYPE_UNKNOWN
;
1280 next_pc
+= sizeof(struct unary_op
);
1284 case FILTER_OP_UNARY_PLUS_S64
:
1285 case FILTER_OP_UNARY_MINUS_S64
:
1286 case FILTER_OP_UNARY_NOT_S64
:
1289 if (!vstack_ax(stack
)) {
1290 printk(KERN_WARNING
"Empty stack\n\n");
1294 switch (vstack_ax(stack
)->type
) {
1298 printk(KERN_WARNING
"Unexpected register type %d for operation\n",
1299 (int) vstack_ax(stack
)->type
);
1304 vstack_ax(stack
)->type
= REG_S64
;
1305 next_pc
+= sizeof(struct unary_op
);
1309 case FILTER_OP_UNARY_NOT
:
1312 if (!vstack_ax(stack
)) {
1313 printk(KERN_WARNING
"Empty stack\n\n");
1317 switch (vstack_ax(stack
)->type
) {
1319 case REG_TYPE_UNKNOWN
:
1322 printk(KERN_WARNING
"Unexpected register type %d for operation\n",
1323 (int) vstack_ax(stack
)->type
);
1328 vstack_ax(stack
)->type
= REG_S64
;
1329 next_pc
+= sizeof(struct unary_op
);
1333 case FILTER_OP_UNARY_BIT_NOT
:
1336 if (!vstack_ax(stack
)) {
1337 printk(KERN_WARNING
"Empty stack\n");
1341 switch (vstack_ax(stack
)->type
) {
1343 case REG_TYPE_UNKNOWN
:
1347 printk(KERN_WARNING
"Unexpected register type %d for operation\n",
1348 (int) vstack_ax(stack
)->type
);
1353 vstack_ax(stack
)->type
= REG_S64
;
1354 next_pc
+= sizeof(struct unary_op
);
1362 struct logical_op
*insn
= (struct logical_op
*) pc
;
1365 /* Add merge point to table */
1366 merge_ret
= merge_point_add_check(mp_table
,
1367 insn
->skip_offset
, stack
);
1373 if (!vstack_ax(stack
)) {
1374 printk(KERN_WARNING
"Empty stack\n\n");
1378 /* There is always a cast-to-s64 operation before a or/and op. */
1379 switch (vstack_ax(stack
)->type
) {
1383 printk(KERN_WARNING
"Incorrect register type %d for operation\n",
1384 (int) vstack_ax(stack
)->type
);
1389 /* Continue to next instruction */
1390 /* Pop 1 when jump not taken */
1391 if (vstack_pop(stack
)) {
1395 next_pc
+= sizeof(struct logical_op
);
1399 /* load field ref */
1400 case FILTER_OP_LOAD_FIELD_REF
:
1402 printk(KERN_WARNING
"Unknown field ref type\n");
1406 /* get context ref */
1407 case FILTER_OP_GET_CONTEXT_REF
:
1409 printk(KERN_WARNING
"Unknown get context ref type\n");
1413 case FILTER_OP_LOAD_FIELD_REF_STRING
:
1414 case FILTER_OP_LOAD_FIELD_REF_SEQUENCE
:
1415 case FILTER_OP_GET_CONTEXT_REF_STRING
:
1416 case FILTER_OP_LOAD_FIELD_REF_USER_STRING
:
1417 case FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE
:
1419 if (vstack_push(stack
)) {
1423 vstack_ax(stack
)->type
= REG_STRING
;
1424 next_pc
+= sizeof(struct load_op
) + sizeof(struct field_ref
);
1427 case FILTER_OP_LOAD_FIELD_REF_S64
:
1428 case FILTER_OP_GET_CONTEXT_REF_S64
:
1430 if (vstack_push(stack
)) {
1434 vstack_ax(stack
)->type
= REG_S64
;
1435 next_pc
+= sizeof(struct load_op
) + sizeof(struct field_ref
);
1439 /* load from immediate operand */
1440 case FILTER_OP_LOAD_STRING
:
1442 struct load_op
*insn
= (struct load_op
*) pc
;
1444 if (vstack_push(stack
)) {
1448 vstack_ax(stack
)->type
= REG_STRING
;
1449 next_pc
+= sizeof(struct load_op
) + strlen(insn
->data
) + 1;
1453 case FILTER_OP_LOAD_STAR_GLOB_STRING
:
1455 struct load_op
*insn
= (struct load_op
*) pc
;
1457 if (vstack_push(stack
)) {
1461 vstack_ax(stack
)->type
= REG_STAR_GLOB_STRING
;
1462 next_pc
+= sizeof(struct load_op
) + strlen(insn
->data
) + 1;
1466 case FILTER_OP_LOAD_S64
:
1468 if (vstack_push(stack
)) {
1472 vstack_ax(stack
)->type
= REG_S64
;
1473 next_pc
+= sizeof(struct load_op
)
1474 + sizeof(struct literal_numeric
);
1478 case FILTER_OP_CAST_TO_S64
:
1481 if (!vstack_ax(stack
)) {
1482 printk(KERN_WARNING
"Empty stack\n");
1486 switch (vstack_ax(stack
)->type
) {
1489 case REG_TYPE_UNKNOWN
:
1492 printk(KERN_WARNING
"Incorrect register type %d for cast\n",
1493 (int) vstack_ax(stack
)->type
);
1497 vstack_ax(stack
)->type
= REG_S64
;
1498 next_pc
+= sizeof(struct cast_op
);
1501 case FILTER_OP_CAST_NOP
:
1503 next_pc
+= sizeof(struct cast_op
);
1508 * Instructions for recursive traversal through composed types.
1510 case FILTER_OP_GET_CONTEXT_ROOT
:
1511 case FILTER_OP_GET_APP_CONTEXT_ROOT
:
1512 case FILTER_OP_GET_PAYLOAD_ROOT
:
1514 if (vstack_push(stack
)) {
1518 vstack_ax(stack
)->type
= REG_PTR
;
1519 next_pc
+= sizeof(struct load_op
);
1523 case FILTER_OP_LOAD_FIELD
:
1526 if (!vstack_ax(stack
)) {
1527 printk(KERN_WARNING
"Empty stack\n\n");
1531 if (vstack_ax(stack
)->type
!= REG_PTR
) {
1532 printk(KERN_WARNING
"Expecting pointer on top of stack\n\n");
1536 vstack_ax(stack
)->type
= REG_TYPE_UNKNOWN
;
1537 next_pc
+= sizeof(struct load_op
);
1541 case FILTER_OP_LOAD_FIELD_S8
:
1542 case FILTER_OP_LOAD_FIELD_S16
:
1543 case FILTER_OP_LOAD_FIELD_S32
:
1544 case FILTER_OP_LOAD_FIELD_S64
:
1545 case FILTER_OP_LOAD_FIELD_U8
:
1546 case FILTER_OP_LOAD_FIELD_U16
:
1547 case FILTER_OP_LOAD_FIELD_U32
:
1548 case FILTER_OP_LOAD_FIELD_U64
:
1551 if (!vstack_ax(stack
)) {
1552 printk(KERN_WARNING
"Empty stack\n\n");
1556 if (vstack_ax(stack
)->type
!= REG_PTR
) {
1557 printk(KERN_WARNING
"Expecting pointer on top of stack\n\n");
1561 vstack_ax(stack
)->type
= REG_S64
;
1562 next_pc
+= sizeof(struct load_op
);
1566 case FILTER_OP_LOAD_FIELD_STRING
:
1567 case FILTER_OP_LOAD_FIELD_SEQUENCE
:
1570 if (!vstack_ax(stack
)) {
1571 printk(KERN_WARNING
"Empty stack\n\n");
1575 if (vstack_ax(stack
)->type
!= REG_PTR
) {
1576 printk(KERN_WARNING
"Expecting pointer on top of stack\n\n");
1580 vstack_ax(stack
)->type
= REG_STRING
;
1581 next_pc
+= sizeof(struct load_op
);
1585 case FILTER_OP_LOAD_FIELD_DOUBLE
:
1588 if (!vstack_ax(stack
)) {
1589 printk(KERN_WARNING
"Empty stack\n\n");
1593 if (vstack_ax(stack
)->type
!= REG_PTR
) {
1594 printk(KERN_WARNING
"Expecting pointer on top of stack\n\n");
1598 vstack_ax(stack
)->type
= REG_DOUBLE
;
1599 next_pc
+= sizeof(struct load_op
);
1603 case FILTER_OP_GET_SYMBOL
:
1604 case FILTER_OP_GET_SYMBOL_FIELD
:
1607 if (!vstack_ax(stack
)) {
1608 printk(KERN_WARNING
"Empty stack\n\n");
1612 if (vstack_ax(stack
)->type
!= REG_PTR
) {
1613 printk(KERN_WARNING
"Expecting pointer on top of stack\n\n");
1617 next_pc
+= sizeof(struct load_op
) + sizeof(struct get_symbol
);
1621 case FILTER_OP_GET_INDEX_U16
:
1624 if (!vstack_ax(stack
)) {
1625 printk(KERN_WARNING
"Empty stack\n\n");
1629 if (vstack_ax(stack
)->type
!= REG_PTR
) {
1630 printk(KERN_WARNING
"Expecting pointer on top of stack\n\n");
1634 next_pc
+= sizeof(struct load_op
) + sizeof(struct get_index_u16
);
1638 case FILTER_OP_GET_INDEX_U64
:
1641 if (!vstack_ax(stack
)) {
1642 printk(KERN_WARNING
"Empty stack\n\n");
1646 if (vstack_ax(stack
)->type
!= REG_PTR
) {
1647 printk(KERN_WARNING
"Expecting pointer on top of stack\n\n");
1651 next_pc
+= sizeof(struct load_op
) + sizeof(struct get_index_u64
);
1657 *_next_pc
= next_pc
;
1662 * Never called concurrently (hash seed is shared).
1664 int lttng_filter_validate_bytecode(struct bytecode_runtime
*bytecode
)
1666 struct mp_table
*mp_table
;
1667 char *pc
, *next_pc
, *start_pc
;
1669 struct vstack stack
;
1671 vstack_init(&stack
);
1673 mp_table
= kzalloc(sizeof(*mp_table
), GFP_KERNEL
);
1675 printk(KERN_WARNING
"Error allocating hash table for bytecode validation\n");
1678 start_pc
= &bytecode
->code
[0];
1679 for (pc
= next_pc
= start_pc
; pc
- start_pc
< bytecode
->len
;
1681 ret
= bytecode_validate_overflow(bytecode
, start_pc
, pc
);
1684 printk(KERN_WARNING
"filter bytecode overflow\n");
1687 dbg_printk("Validating op %s (%u)\n",
1688 lttng_filter_print_op((unsigned int) *(filter_opcode_t
*) pc
),
1689 (unsigned int) *(filter_opcode_t
*) pc
);
1692 * For each instruction, validate the current context
1693 * (traversal of entire execution flow), and validate
1694 * all merge points targeting this instruction.
1696 ret
= validate_instruction_all_contexts(bytecode
, mp_table
,
1697 &stack
, start_pc
, pc
);
1700 ret
= exec_insn(bytecode
, mp_table
, &stack
, &next_pc
, pc
);
1705 if (delete_all_nodes(mp_table
)) {
1707 printk(KERN_WARNING
"Unexpected merge points\n");