4 * LTTng modules filter code.
6 * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
27 #include <linux/list.h>
28 #include <linux/slab.h>
30 #include <lttng-filter.h>
32 static const char *opnames
[] = {
33 [ FILTER_OP_UNKNOWN
] = "UNKNOWN",
35 [ FILTER_OP_RETURN
] = "RETURN",
38 [ FILTER_OP_MUL
] = "MUL",
39 [ FILTER_OP_DIV
] = "DIV",
40 [ FILTER_OP_MOD
] = "MOD",
41 [ FILTER_OP_PLUS
] = "PLUS",
42 [ FILTER_OP_MINUS
] = "MINUS",
43 [ FILTER_OP_RSHIFT
] = "RSHIFT",
44 [ FILTER_OP_LSHIFT
] = "LSHIFT",
45 [ FILTER_OP_BIN_AND
] = "BIN_AND",
46 [ FILTER_OP_BIN_OR
] = "BIN_OR",
47 [ FILTER_OP_BIN_XOR
] = "BIN_XOR",
49 /* binary comparators */
50 [ FILTER_OP_EQ
] = "EQ",
51 [ FILTER_OP_NE
] = "NE",
52 [ FILTER_OP_GT
] = "GT",
53 [ FILTER_OP_LT
] = "LT",
54 [ FILTER_OP_GE
] = "GE",
55 [ FILTER_OP_LE
] = "LE",
57 /* string binary comparators */
58 [ FILTER_OP_EQ_STRING
] = "EQ_STRING",
59 [ FILTER_OP_NE_STRING
] = "NE_STRING",
60 [ FILTER_OP_GT_STRING
] = "GT_STRING",
61 [ FILTER_OP_LT_STRING
] = "LT_STRING",
62 [ FILTER_OP_GE_STRING
] = "GE_STRING",
63 [ FILTER_OP_LE_STRING
] = "LE_STRING",
65 /* s64 binary comparators */
66 [ FILTER_OP_EQ_S64
] = "EQ_S64",
67 [ FILTER_OP_NE_S64
] = "NE_S64",
68 [ FILTER_OP_GT_S64
] = "GT_S64",
69 [ FILTER_OP_LT_S64
] = "LT_S64",
70 [ FILTER_OP_GE_S64
] = "GE_S64",
71 [ FILTER_OP_LE_S64
] = "LE_S64",
73 /* double binary comparators */
74 [ FILTER_OP_EQ_DOUBLE
] = "EQ_DOUBLE",
75 [ FILTER_OP_NE_DOUBLE
] = "NE_DOUBLE",
76 [ FILTER_OP_GT_DOUBLE
] = "GT_DOUBLE",
77 [ FILTER_OP_LT_DOUBLE
] = "LT_DOUBLE",
78 [ FILTER_OP_GE_DOUBLE
] = "GE_DOUBLE",
79 [ FILTER_OP_LE_DOUBLE
] = "LE_DOUBLE",
81 /* Mixed S64-double binary comparators */
82 [ FILTER_OP_EQ_DOUBLE_S64
] = "EQ_DOUBLE_S64",
83 [ FILTER_OP_NE_DOUBLE_S64
] = "NE_DOUBLE_S64",
84 [ FILTER_OP_GT_DOUBLE_S64
] = "GT_DOUBLE_S64",
85 [ FILTER_OP_LT_DOUBLE_S64
] = "LT_DOUBLE_S64",
86 [ FILTER_OP_GE_DOUBLE_S64
] = "GE_DOUBLE_S64",
87 [ FILTER_OP_LE_DOUBLE_S64
] = "LE_DOUBLE_S64",
89 [ FILTER_OP_EQ_S64_DOUBLE
] = "EQ_S64_DOUBLE",
90 [ FILTER_OP_NE_S64_DOUBLE
] = "NE_S64_DOUBLE",
91 [ FILTER_OP_GT_S64_DOUBLE
] = "GT_S64_DOUBLE",
92 [ FILTER_OP_LT_S64_DOUBLE
] = "LT_S64_DOUBLE",
93 [ FILTER_OP_GE_S64_DOUBLE
] = "GE_S64_DOUBLE",
94 [ FILTER_OP_LE_S64_DOUBLE
] = "LE_S64_DOUBLE",
97 [ FILTER_OP_UNARY_PLUS
] = "UNARY_PLUS",
98 [ FILTER_OP_UNARY_MINUS
] = "UNARY_MINUS",
99 [ FILTER_OP_UNARY_NOT
] = "UNARY_NOT",
100 [ FILTER_OP_UNARY_PLUS_S64
] = "UNARY_PLUS_S64",
101 [ FILTER_OP_UNARY_MINUS_S64
] = "UNARY_MINUS_S64",
102 [ FILTER_OP_UNARY_NOT_S64
] = "UNARY_NOT_S64",
103 [ FILTER_OP_UNARY_PLUS_DOUBLE
] = "UNARY_PLUS_DOUBLE",
104 [ FILTER_OP_UNARY_MINUS_DOUBLE
] = "UNARY_MINUS_DOUBLE",
105 [ FILTER_OP_UNARY_NOT_DOUBLE
] = "UNARY_NOT_DOUBLE",
108 [ FILTER_OP_AND
] = "AND",
109 [ FILTER_OP_OR
] = "OR",
112 [ FILTER_OP_LOAD_FIELD_REF
] = "LOAD_FIELD_REF",
113 [ FILTER_OP_LOAD_FIELD_REF_STRING
] = "LOAD_FIELD_REF_STRING",
114 [ FILTER_OP_LOAD_FIELD_REF_SEQUENCE
] = "LOAD_FIELD_REF_SEQUENCE",
115 [ FILTER_OP_LOAD_FIELD_REF_S64
] = "LOAD_FIELD_REF_S64",
116 [ FILTER_OP_LOAD_FIELD_REF_DOUBLE
] = "LOAD_FIELD_REF_DOUBLE",
118 /* load from immediate operand */
119 [ FILTER_OP_LOAD_STRING
] = "LOAD_STRING",
120 [ FILTER_OP_LOAD_S64
] = "LOAD_S64",
121 [ FILTER_OP_LOAD_DOUBLE
] = "LOAD_DOUBLE",
124 [ FILTER_OP_CAST_TO_S64
] = "CAST_TO_S64",
125 [ FILTER_OP_CAST_DOUBLE_TO_S64
] = "CAST_DOUBLE_TO_S64",
126 [ FILTER_OP_CAST_NOP
] = "CAST_NOP",
128 /* get context ref */
129 [ FILTER_OP_GET_CONTEXT_REF
] = "GET_CONTEXT_REF",
130 [ FILTER_OP_GET_CONTEXT_REF_STRING
] = "GET_CONTEXT_REF_STRING",
131 [ FILTER_OP_GET_CONTEXT_REF_S64
] = "GET_CONTEXT_REF_S64",
132 [ FILTER_OP_GET_CONTEXT_REF_DOUBLE
] = "GET_CONTEXT_REF_DOUBLE",
134 /* load userspace field ref */
135 [ FILTER_OP_LOAD_FIELD_REF_USER_STRING
] = "LOAD_FIELD_REF_USER_STRING",
136 [ FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE
] = "LOAD_FIELD_REF_USER_SEQUENCE",
139 * load immediate star globbing pattern (literal string)
142 [ FILTER_OP_LOAD_STAR_GLOB_STRING
] = "LOAD_STAR_GLOB_STRING",
144 /* globbing pattern binary operator: apply to */
145 [ FILTER_OP_EQ_STAR_GLOB_STRING
] = "EQ_STAR_GLOB_STRING",
146 [ FILTER_OP_NE_STAR_GLOB_STRING
] = "NE_STAR_GLOB_STRING",
149 const char *lttng_filter_print_op(enum filter_op op
)
151 if (op
>= NR_FILTER_OPS
)
158 int apply_field_reloc(struct lttng_event
*event
,
159 struct bytecode_runtime
*runtime
,
160 uint32_t runtime_len
,
161 uint32_t reloc_offset
,
162 const char *field_name
)
164 const struct lttng_event_desc
*desc
;
165 const struct lttng_event_field
*fields
, *field
= NULL
;
166 unsigned int nr_fields
, i
;
167 struct field_ref
*field_ref
;
169 uint32_t field_offset
= 0;
171 dbg_printk("Apply field reloc: %u %s\n", reloc_offset
, field_name
);
173 /* Lookup event by name */
177 fields
= desc
->fields
;
180 nr_fields
= desc
->nr_fields
;
181 for (i
= 0; i
< nr_fields
; i
++) {
182 if (!strcmp(fields
[i
].name
, field_name
)) {
186 /* compute field offset */
187 switch (fields
[i
].type
.atype
) {
190 field_offset
+= sizeof(int64_t);
194 field_offset
+= sizeof(unsigned long);
195 field_offset
+= sizeof(void *);
198 field_offset
+= sizeof(void *);
200 case atype_struct
: /* Unsupported. */
201 case atype_array_compound
: /* Unsupported. */
202 case atype_sequence_compound
: /* Unsupported. */
203 case atype_variant
: /* Unsupported. */
211 /* Check if field offset is too large for 16-bit offset */
212 if (field_offset
> LTTNG_KERNEL_FILTER_BYTECODE_MAX_LEN
- 1)
216 op
= (struct load_op
*) &runtime
->data
[reloc_offset
];
217 field_ref
= (struct field_ref
*) op
->data
;
218 switch (field
->type
.atype
) {
221 op
->op
= FILTER_OP_LOAD_FIELD_REF_S64
;
226 op
->op
= FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE
;
228 op
->op
= FILTER_OP_LOAD_FIELD_REF_SEQUENCE
;
232 op
->op
= FILTER_OP_LOAD_FIELD_REF_USER_STRING
;
234 op
->op
= FILTER_OP_LOAD_FIELD_REF_STRING
;
236 case atype_struct
: /* Unsupported. */
237 case atype_array_compound
: /* Unsupported. */
238 case atype_sequence_compound
: /* Unsupported. */
239 case atype_variant
: /* Unsupported. */
244 field_ref
->offset
= (uint16_t) field_offset
;
249 int apply_context_reloc(struct lttng_event
*event
,
250 struct bytecode_runtime
*runtime
,
251 uint32_t runtime_len
,
252 uint32_t reloc_offset
,
253 const char *context_name
)
255 struct field_ref
*field_ref
;
257 struct lttng_ctx_field
*ctx_field
;
260 dbg_printk("Apply context reloc: %u %s\n", reloc_offset
, context_name
);
262 /* Get context index */
263 idx
= lttng_get_context_index(lttng_static_ctx
, context_name
);
267 /* Check if idx is too large for 16-bit offset */
268 if (idx
> LTTNG_KERNEL_FILTER_BYTECODE_MAX_LEN
- 1)
271 /* Get context return type */
272 ctx_field
= <tng_static_ctx
->fields
[idx
];
273 op
= (struct load_op
*) &runtime
->data
[reloc_offset
];
274 field_ref
= (struct field_ref
*) op
->data
;
275 switch (ctx_field
->event_field
.type
.atype
) {
278 op
->op
= FILTER_OP_GET_CONTEXT_REF_S64
;
280 /* Sequence and array supported as string */
284 BUG_ON(ctx_field
->event_field
.user
);
285 op
->op
= FILTER_OP_GET_CONTEXT_REF_STRING
;
287 case atype_struct
: /* Unsupported. */
288 case atype_array_compound
: /* Unsupported. */
289 case atype_sequence_compound
: /* Unsupported. */
290 case atype_variant
: /* Unsupported. */
294 /* set offset to context index within channel contexts */
295 field_ref
->offset
= (uint16_t) idx
;
300 int apply_reloc(struct lttng_event
*event
,
301 struct bytecode_runtime
*runtime
,
302 uint32_t runtime_len
,
303 uint32_t reloc_offset
,
308 dbg_printk("Apply reloc: %u %s\n", reloc_offset
, name
);
310 /* Ensure that the reloc is within the code */
311 if (runtime_len
- reloc_offset
< sizeof(uint16_t))
314 op
= (struct load_op
*) &runtime
->data
[reloc_offset
];
316 case FILTER_OP_LOAD_FIELD_REF
:
317 return apply_field_reloc(event
, runtime
, runtime_len
,
319 case FILTER_OP_GET_CONTEXT_REF
:
320 return apply_context_reloc(event
, runtime
, runtime_len
,
323 printk(KERN_WARNING
"Unknown reloc op type %u\n", op
->op
);
330 int bytecode_is_linked(struct lttng_filter_bytecode_node
*filter_bytecode
,
331 struct lttng_event
*event
)
333 struct lttng_bytecode_runtime
*bc_runtime
;
335 list_for_each_entry(bc_runtime
,
336 &event
->bytecode_runtime_head
, node
) {
337 if (bc_runtime
->bc
== filter_bytecode
)
344 * Take a bytecode with reloc table and link it to an event to create a
348 int _lttng_filter_event_link_bytecode(struct lttng_event
*event
,
349 struct lttng_filter_bytecode_node
*filter_bytecode
,
350 struct list_head
*insert_loc
)
352 int ret
, offset
, next_offset
;
353 struct bytecode_runtime
*runtime
= NULL
;
354 size_t runtime_alloc_len
;
356 if (!filter_bytecode
)
358 /* Bytecode already linked */
359 if (bytecode_is_linked(filter_bytecode
, event
))
362 dbg_printk("Linking...\n");
364 /* We don't need the reloc table in the runtime */
365 runtime_alloc_len
= sizeof(*runtime
) + filter_bytecode
->bc
.reloc_offset
;
366 runtime
= kzalloc(runtime_alloc_len
, GFP_KERNEL
);
371 runtime
->p
.bc
= filter_bytecode
;
372 runtime
->len
= filter_bytecode
->bc
.reloc_offset
;
373 /* copy original bytecode */
374 memcpy(runtime
->data
, filter_bytecode
->bc
.data
, runtime
->len
);
376 * apply relocs. Those are a uint16_t (offset in bytecode)
377 * followed by a string (field name).
379 for (offset
= filter_bytecode
->bc
.reloc_offset
;
380 offset
< filter_bytecode
->bc
.len
;
381 offset
= next_offset
) {
382 uint16_t reloc_offset
=
383 *(uint16_t *) &filter_bytecode
->bc
.data
[offset
];
385 (const char *) &filter_bytecode
->bc
.data
[offset
+ sizeof(uint16_t)];
387 ret
= apply_reloc(event
, runtime
, runtime
->len
, reloc_offset
, name
);
391 next_offset
= offset
+ sizeof(uint16_t) + strlen(name
) + 1;
393 /* Validate bytecode */
394 ret
= lttng_filter_validate_bytecode(runtime
);
398 /* Specialize bytecode */
399 ret
= lttng_filter_specialize_bytecode(runtime
);
403 runtime
->p
.filter
= lttng_filter_interpret_bytecode
;
404 runtime
->p
.link_failed
= 0;
405 list_add_rcu(&runtime
->p
.node
, insert_loc
);
406 dbg_printk("Linking successful.\n");
410 runtime
->p
.filter
= lttng_filter_false
;
411 runtime
->p
.link_failed
= 1;
412 list_add_rcu(&runtime
->p
.node
, insert_loc
);
414 dbg_printk("Linking failed.\n");
418 void lttng_filter_sync_state(struct lttng_bytecode_runtime
*runtime
)
420 struct lttng_filter_bytecode_node
*bc
= runtime
->bc
;
422 if (!bc
->enabler
->enabled
|| runtime
->link_failed
)
423 runtime
->filter
= lttng_filter_false
;
425 runtime
->filter
= lttng_filter_interpret_bytecode
;
429 * Link bytecode for all enablers referenced by an event.
431 void lttng_enabler_event_link_bytecode(struct lttng_event
*event
,
432 struct lttng_enabler
*enabler
)
434 struct lttng_filter_bytecode_node
*bc
;
435 struct lttng_bytecode_runtime
*runtime
;
437 /* Can only be called for events with desc attached */
438 WARN_ON_ONCE(!event
->desc
);
440 /* Link each bytecode. */
441 list_for_each_entry(bc
, &enabler
->filter_bytecode_head
, node
) {
443 struct list_head
*insert_loc
;
445 list_for_each_entry(runtime
,
446 &event
->bytecode_runtime_head
, node
) {
447 if (runtime
->bc
== bc
) {
452 /* Skip bytecode already linked */
457 * Insert at specified priority (seqnum) in increasing
460 list_for_each_entry_reverse(runtime
,
461 &event
->bytecode_runtime_head
, node
) {
462 if (runtime
->bc
->bc
.seqnum
< bc
->bc
.seqnum
) {
464 insert_loc
= &runtime
->node
;
468 /* Add to head to list */
469 insert_loc
= &event
->bytecode_runtime_head
;
471 dbg_printk("linking bytecode\n");
472 ret
= _lttng_filter_event_link_bytecode(event
, bc
,
475 dbg_printk("[lttng filter] warning: cannot link event bytecode\n");
481 * We own the filter_bytecode if we return success.
483 int lttng_filter_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
484 struct lttng_filter_bytecode_node
*filter_bytecode
)
486 list_add(&filter_bytecode
->node
, &enabler
->filter_bytecode_head
);
490 void lttng_free_enabler_filter_bytecode(struct lttng_enabler
*enabler
)
492 struct lttng_filter_bytecode_node
*filter_bytecode
, *tmp
;
494 list_for_each_entry_safe(filter_bytecode
, tmp
,
495 &enabler
->filter_bytecode_head
, node
) {
496 kfree(filter_bytecode
);
500 void lttng_free_event_filter_runtime(struct lttng_event
*event
)
502 struct bytecode_runtime
*runtime
, *tmp
;
504 list_for_each_entry_safe(runtime
, tmp
,
505 &event
->bytecode_runtime_head
, p
.node
) {